Composite electrolytes

ABSTRACT

Set forth herein are electrolyte compositions that include both organic and inorganic constituent components and which are suitable for use in rechargeable batteries. Also set forth herein are methods and systems for making and using these composite electrolytes.

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/184,028, filed Jun. 24, 2015, and also claims priority to U.S.Provisional Patent Application No. 62/240,576, filed Oct. 13, 2015, theentire contents of each provisional patent application are hereinincorporated by reference in their entirety for all purposes.

US NONPROVISIONAL PATENT APPLICATION

Inventors Mailing Address Kim Van Berkel, 1730 Technology Drive acitizen of New Zealand San Jose, California 95110 Tim Holme, 1730Technology Drive a citizen of the United States of America San Jose,California 95110 Mohit Singh, 1730 Technology Drive a citizen of IndiaSan Jose, California 95110 Amal Mehrotra, 1730 Technology Drive acitizen of India San Jose, California 95110 Zhebo Chen, 1730 TechnologyDrive a citizen of the United States of America San Jose, California95110 Kian Kerman, 1730 Technology Drive a citizen of the United Statesof America San Jose, California 95110 Wes Hermann, 1730 Technology Drivea citizen of the United States of America San Jose, California 95110William Hudson, 1730 Technology Drive a citizen of the United States ofAmerica San Jose, California 95110

Entity: Small BACKGROUND

As the prevalence of consumer electronics (e.g., mobile phones, tablets,and laptop computers) and electrified-vehicle (i.e., EV) automobiles(e.g., plug-in hybrids and BEVs) has increased, so too has the demandfor better performing energy storage devices which are required to powerthese consumer electronics and vehicles. While rechargeable lithium (Li)ion batteries are popular energy storage devices for consumerelectronics, currently available rechargeable lithium (Li) ion batteriesare still too limited with respect to their energy density and poweroutput for mainstream consumer adoption in automotive as well as otherenergy-intensive application. In order to improve upon the energydensity and power output of rechargeable Li batteries, Li-metal has beenproposed as a next-generation negative electrode material since suchelectrodes theoretically produce the highest energy densities possibleby minimizing a battery's discharged voltage (i.e., V of Li in Li-metalis 0V) and maximizing the charged voltage [See, e.g., Andre, Dave, etal., J. Mater. Chem. A, DOI: 10.1039/c5ta00361j, (2015)]. By pairing aLi-metal negative electrode with a highly ion-conducting solid stateelectrolyte, the stored energy in a highly energy-dense rechargeable Liion batteries should theoretically be accessed at commercially viablepower rates.

When a Li-rechargeable battery discharges, Li⁺ ions conduct through anelectrolyte from a negative to a positive electrode and vice versaduring charge. This process produces electrical energy(Energy=Voltage×Current) in a circuit connecting the electrodes and thatis electrically insulated from, but parallel to, the Li⁺ conductionpath; the Voltage (V versus Li) being a function of the chemicalpotential difference for Li situated in the positive electrode ascompared to the negative electrode. In order to use Li-metal negativeelectrodes, however, new solid state electrolytes are required as theknown and widely used liquid electrolytes are chemically incompatiblewith Li-metal.

Solid state Li-rechargeable batteries which include solid stateelectrolytes are an attractive alternative to conventionalLi-rechargeable batteries, in part due to the aforementioned higherenergy densities (e.g., gravimetric or volumetric) and power rates butalso due to their safety attributes which are related to the absence ofan flammable organic liquid electrolyte. Although Li-metal negativeelectrodes maximize a battery's energy density, Li-metal isunfortunately highly reactive with most electrolytes and has a largevolume change (e.g., contraction and expansion) when discharged andcharged. This volume change mechanically strains, and can crack, a solidstate electrolyte which contacts the Li-metal. This mechanical stabilityissue is worsened if the electrolyte also chemically reacts withLi-metal. To date, there are no viable commercially available solutionsto either of these chemical or mechanical stability problems, nor arethere solutions to other problems such as resistance/impedance gain,which are associated with interfacing Li-metal negative electrodes withsolid state electrolytes.

Some solid state electrolytes have been analyzed, such as oxide- orsulfide-based electrolytes. See, for example, U.S. Pat. Nos. 8,658,317,8,092,941, 7,901,658, 6,277,524 and 8,697,292; U.S. Patent ApplicationPublication Nos. 2013/0085055, 2011/0281175, 2014/0093785, 2014/0170504,2014/0065513 and 2010/0047696; also Bonderer, et al. Journal of theAmerican Ceramic Society, 2010, 93(11):3624-3631; Murugan, et al., AngewChem. Int. Ed. 2007, 46, 7778-7781; Buschmann, et al., Phys. Chem. Chem.Phys., 2011, 13, 19378-19392; Buschmann, et al., Journal of PowerSources 206 (2012) 236-244; Kotobuki, et al., Journal of Power Sources196 (2011) 7750-7754; and Jin, et al., Journal of Power Sources 196(2011) 8683-8687. Some composites of these electrolytes are also known.See, for example, Skaarup, Steen, et al., Solid State Ionics 28-30(1988) 975-978; Skaarup, Steen, et al., Solid State Ionics 40/41 (1990)1021-1024; Nairn, K., et al., Solid State Ionics 86-88 (1996) 589-593;Nairn, K., et al., Solid State Ionics 121 (1999) 115-119; Kumar, Binod,et al., Journal of Electroceramics, 5:2, 127-139, 2000; Wang, Yan-Jie,et al., Journal of Applied Polymer Science, Vol. 102, 1328-1334 (2006);Thokchom, J. S., et al., J. Am Ceram. Soc., 90 [2] 462-466 (2007);Wieczorek, W. et al., Electronic Materials: Science and TechnologyVolume 10, 2008, pp 1-7; Li, Qin, et al, Solid State Ionic 268 (2014)156-161; Aetukuri, N. B., et al., Adv. Energy Mater., 2015, pages 1-6;Lim, Y. J., et al., ChemPlusChem, DOI: 10.1002/cplu.201500106; Liu, W.,et al., DOI: 10.1021/acs.nanolett.5b00600; and Nam, Y. J., et al., NanoLett., 2015, 15 (5), pp 3317-3323), Despite their ability to conduct Li⁺ions, these solid electrolytes have yet to demonstrate sufficiently highion conductivity, sufficiently long cycle-ability, a high coulombicefficiency at high cumulative Li throughput, the ability to prevent theformation of lithium dendrites, or the ability to be formulated orprepared with the proper morphology (e.g., thin, flexible film) orsufficient particle connectivity (i.e., particle-particle necking) tofunction as required for commercial applications.

Conventional Li-rechargeable batteries uses a liquid electrolyte and athin polymer membrane disposed between two electrodes. The polymermembrane is sometimes referred to as a separator. The polymer membraneis used primarily to prevent direct contact between the two electrodes.Small holes in the polymer membrane allow the liquid electrolyte to flowbetween the two electrodes for ionic conductivity. Formation of lithiumdendrites can be slowed, though not prevented, by minimizing nucleationpoints available for the dendrites to grow from, e.g., by using smoothelectrodes formed by passing these electrodes through a roll press. Whendendrites start growing in such a cell, the polymer membrane is notrobust enough to prevent these growing dendrites from piercing throughthe membrane and eventually causing the internal short between the twoelectrodes. What is needed, in the relevant field, then is a robustelectrolyte system which may be capable of blocking dendrites frompiercing through the system. What is needed, in the relevant field, is,for example, an electrolyte system which can act as a mechanical barrierto prevent the growth of dendrites in the direction between twoelectrodes. If a solid electrolyte is combined with one or morepolymers, the mechanical properties of this combination may provideoperable electrolyte characteristics (e.g., ionic conductivity,electrical resistance) and mechanical characteristics (e.g., yieldstrength, yield strain, ultimate strength, and ultimate strain) that arecapable of withstanding dendrite growth and preventing dendrites frompiercing through the composite electrolyte. The minimum mechanicalcharacteristics needed to block lithium dendrites may depend onlocalized voltage values, interface geometry, and other characteristics.Furthermore, small variations in composition of composite electrolytesmay yield substantial changes in these mechanical characteristics.

There is therefore a series of problems in the relevant field related tosolid state electrolytes which are chemically and mechanicallycompatible with Li-metal electrodes, are robust, and have sufficientionic conductivity for commercial battery applications. What is neededin the relevant field is, for example, chemically and mechanicallystable thin film solid state electrolytes with sufficient conductivityfor energy dense rechargeable batteries and which accommodate Li-metal'svolume expansion and contraction during battery charge and discharge.The instant disclosure sets forth electrolytes, for example, compositeelectrolytes, in addition to methods for making and using theseelectrolytes and composite electrolytes. The instant disclosure setsforth other solutions to problems in the relevant field.

SUMMARY

In one embodiment, set forth herein is an electrolyte including aninorganic material embedded in an organic material. In some examples,the electrolyte has a fracture strength of greater than 5 MPa and lessthan 250 MPa.

In a second embodiment, set forth herein is an electrochemical deviceincluding an electrolyte or composite electrolyte described herein.

In a third embodiment, set forth herein is an electrolyte including aninorganic material and an organic material, wherein the inorganicmaterial is embedded in the organic material, and the organic materialis molded around, adsorbed to, bonded to, or entangled with the surfaceof the inorganic material or a particle thereof.

In a forth embodiment, set forth herein are electrochemical cells whichinclude a positive electrode, a negative electrode, and a compositeelectrolyte layer. In these embodiments, at least one compositeelectrolyte layer is positioned between the positive electrode andnegative electrode. The composite electrolyte layer includes a polymerand an inorganic solid state electrolyte such that the amount of theinorganic component is maximized in the composite without the compositemechanically degrading on account of too high of an inorganic solidloading. In some embodiments of these composites, the volumetric ratioof inorganic solid state electrolyte to polymer is greater than 1. Insome of these embodiments, either or both of the positive electrode andnegative electrodes directly contact the inorganic solid stateelectrolyte component of the composite electrolyte. In some embodiments,the adjoining sides of the electrolyte directly interfacing the positiveor negative electrodes are polished, etched, or plasma treated to removepolymer at the surface and to expose a inorganic solid state electrolytecomponents at the surface.

In a fifth embodiment, set forth herein are thin film electrolytes thatinclude an inorganic solid state electrolyte and a polymer. In some ofthese electrolytes, the film has at least one textured surface, and thepolymer bonds to the at least one textured surface. In some examples,the film has a thickness that is between about 10 nm to 100 μm. Incertain examples, the inorganic electrolyte is exposed at both sides ofthe film which have the highest surface areas.

In a sixth embodiment, set forth herein are methods of making acomposite electrolyte thin film, wherein the film, has a top surface anda bottom surface, includes a polymer and an inorganic solid stateelectrolyte, and has a volumetric ratio of inorganic solid stateelectrolyte to polymer that is greater than 1. In some examples, themethod includes providing a monodisperse collection of inorganic solidstate electrolyte particles, providing a polymer, optionally providing asolvent, mixing the polymer and solid state electrolyte to form amixture wherein the volumetric ratio of inorganic solid stateelectrolyte to polymer is greater than 1, casting or extruding themixture, and drying the mixture to form a dried film. In some examples,the method further includes treating the surface of the dried film toexpose the inorganic solid state electrolyte at the top and bottomsurfaces.

In a seventh embodiment, set forth herein are methods of making acomposite electrolyte thin film, which includes the following steps:providing a mixture which includes inorganic solid state electrolyteprecursors, inorganic solid state electrolytes, binders, polymers,solvents, or combinations thereof, casting the mixture with a template,calcining the mixture with a template to form a calcined inorganic solidstate electrolyte having void spaces, backfilling the void spaces with apolymer, wherein the polymer includes those polymers described in thispatent application, wherein the volumetric ratio of inorganic solidstate electrolyte to polymer is greater than 1. In some examples, themethod further includes treating the surface of the dried film to exposethe inorganic solid state electrolyte at the top and bottom surfaces.The treating can include a variety of known treatment methods such as,but not limited to, radiation (e.g., ultraviolet radiation) or chemicaltreatment (e.g., HF exposure)

In an eighth embodiment, set forth herein are methods of making acomposite electrolyte thin film, wherein the film, has a top surface anda bottom surface, comprises a polymer and an inorganic solid stateelectrolyte, and has a volumetric ratio of inorganic solid stateelectrolyte to polymer that is greater than 1. In some examples, themethods herein include providing a mixture comprising inorganic solidstate electrolyte precursors, inorganic solid state electrolytes,binders, polymers, solvents, or combinations thereof, casting themixture, imprinting the mixture with a template, removing the template,sintering the mixture to form a sintered inorganic solid stateelectrolyte having a textured surface, backfilling the textured surfacewith a polymer, selected from those polymers described herein, whereinthe volumetric ratio of inorganic solid state electrolyte to polymer isgreater than 1. In some examples, the method further includes treatingthe surface of the dried film to expose the inorganic solid stateelectrolyte at the top and bottom surfaces.

In a ninth embodiment, set forth herein are methods of making acomposite electrolyte membrane having a top surface and a bottom surfaceand comprising a polymer and an inorganic solid state electrolyte,wherein the volumetric ratio of inorganic solid state electrolyte topolymer is >1, including the following steps providing an organicsubstrate or mesh, proving an inorganic solid state electrolyteprecursor slurry, casting the slurry onto the substrate or mesh,calcining the slurry on the substrate or mesh to remove the substrate ormesh and form an inorganic solid state electrolyte having void spaces,backfilling the void spaces with a polymer, selected from those polymersdescribed herein, wherein the volumetric ratio of inorganic solid stateelectrolyte to polymer is greater than 1. In some examples, the methodfurther includes treating the surface of the dried film to expose theinorganic solid state electrolyte at the top and bottom surfaces.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example method for making a single-particle thicknessextruded composite film.

FIG. 2 shows an example method for making a particle-templated andback-filled composite film.

FIG. 3 shows an example method for making a mesh-templated andback-filled composite film.

FIG. 4 shows an example method for making an imprinted and back-filledcomposite film.

FIG. 5 shows an example method for making a templated and back-filledfilm.

FIG. 6 illustrates an example composite film having a thickness aboutthe size of an inorganic particle therein.

FIG. 7 illustrates an example cracked composite film with back-filledpolymer.

FIG. 8 a surface profile for the sintered film prepared according toparticle-template method of Example 2 and as observed on a KeyenceVK-X100 instrument that measures surface roughness using a laser.

FIG. 9 is a magnified optical image of an imprinted green film ofExample 2.

FIG. 10 is a surface profile for a sintered film prepared according tothe imprinting method of Example 2 as observed on a Keyence VK-X100instrument that measures surface roughness using a laser.

FIGS. 11 and 12 are surface profiles for the sintered film preparedaccording to Example 2 as observed on a Keyence VK-X100 instrument thatmeasures surface roughness using a laser.

FIG. 13 shows a cross-sectional scanning electron microscopy (SEM)images of a sintered lithium-stuffed garnet film, which is notback-filled with a polymer, prepared according to an embodiment ofExample 2.

FIG. 14 shows a cross-sectional scanning electron microscopy (SEM)images of a sintered and back-filled lithium-stuffed garnet filmprepared according to an embodiment of Example 2.

FIG. 15 show ionic conductivity values for a variety of compositeelectrolytes prepared according to Example 3.

FIG. 16 shows conductivity data for an extruded polymer (e.g.,polypropylene) containing composites of LSTPS to Example 5, in which themass loading of LSTPS was kept constant but the polymers used wasvaried.

FIG. 17A show a high conductivity and low porosity sample (30 wt %Polypropylene, 70 wt % LSTPS) used to generate the data in FIG. 16.

FIG. 17B show a high conductivity and low porosity sample (30 wt %Polypropylene, 70 wt % LSTPS) used to generate the data in FIG. 16.

FIG. 18 show DC cycling of Li at 80° C. in a sulfide composite of 80%w/w LTSPS in polypropylene.

FIG. 19 show area-specific resistance for a sulfide composite of 80% w/wLTSPS in polypropylene.

FIG. 20 show a plot of conductivity for a sulfide electrolyte compositeof 80% w/w LPS:LiI in polypropylene.

FIG. 21 show impedance measurements for a sulfide electrolyte compositeof 80% w/w LTSPS in polypropylene.

FIG. 22 show impedance measurements for a sulfide electrolyte compositeof 80% w/w LTSPS in polypropylene and demonstrates the effect observedwhen the composites are polished.

FIG. 23 show Lithium plating/stripping cycling data for a sulfideelectrolyte composite of 80% w/w LTSPS in polypropylene.

FIG. 24 shows an SEM image for a sulfide electrolyte composite of 80%w/w LTSPS in polypropylene.

FIG. 25 shows a plot of impedance as a function of time for a compositeof LSTPS and polypropylene.

FIG. 26 shows a plot of impedance as a function of time for a compositeof LSTPS and polypropylene.

FIG. 27 shows a plot of impedance as a function of time for a compositeof LiBH₄:LiI and polypropylene.

FIG. 28 illustrates an advantage for polishing an extruded thin filmcomposite of LiBH₄:LiI and polypropylene which was formed bymelt-pressing.

FIG. 29 shows a plot of Conductivity (S/cm) as a function of LSTPSvolume %.

FIG. 30 illustrates the beneficial effect of plasma etching the LSTPSpolypropylene composite of Example 5.

FIG. 31 illustrates stress-stain plots for different combinations ofsolid electrolyte particles and linear low density polyethylene (LLDPE).

FIG. 32 illustrates stress-stain plots for different combinations ofsolid electrolyte particles and cross-linked polybutadiene (PB).

FIG. 33 illustrates stress-stain plots for different combinations ofsolid electrolyte particles and polypropylene (PP).

FIG. 34 is a summary of yield strength values plotting these values as afunction of solid electrolyte loading.

FIG. 35 is a summary of ultimate strength values plotting these valuesas a function of solid electrolyte loading.

FIG. 36 is a summary of yield strain values plotting these values as afunction of solid electrolyte loading.

FIG. 37 is a summary of ultimate strain values plotting these values asa function of solid electrolyte loading.

FIGS. 38A and 38B are SEM images of fracture interfaces of two compositeelectrolytes.

FIG. 39 shows X-ray photo-electron spectroscopy (XPS) for the LPSImaterial made in Example 14.

FIG. 40 shows XPS for the LPSI-composite material made in Example 14.

FIG. 41 shows Li—Li symmetric cell cycling for the LPSI composite withpolyethylene binder prepared in Example, cycled at 80° C., with 20 um Liper cycle.

FIG. 42 shows Li—Li symmetric cell cycling for the LPSI composite withpolybutadiene binder made in Example, cycled 80° C., with 20 um Li percycle.

FIG. 43 shows Li—Li symmetric cell cycling for the LPSI composite withepoxy binder made in Example 18, cycled at 80° C., with 20 um Li percycle.

FIG. 44 shows the Concentric Ring Fixture used to measure the ring onring fracture test.

The figures depict various embodiments of the present disclosure forpurposes of illustration only. One skilled in the art will readilyrecognize from the following discussion that alternative embodiments ofthe structures and methods illustrated herein may be employed withoutdeparting from the principles described herein.

DETAILED DESCRIPTION

The following description is presented to enable one of ordinary skillin the art to make and use the disclosed subject matter and toincorporate it in the context of particular applications. Variousmodifications, as well as a variety of uses in different applicationswill be readily apparent to those skilled in the art, and the generalprinciples defined herein may be applied to a wide range of embodiments.Thus, the present disclosure is not intended to be limited to theembodiments presented, but is to be accorded the widest scope consistentwith the principles and novel features disclosed herein.

In the following detailed description, numerous specific details are setforth in order to provide a more thorough understanding of the presentdisclosure. However, it will be apparent to one skilled in the art thatthe present disclosure may be practiced without necessarily beinglimited to these specific details. In other instances, well-knownstructures and devices are shown in block diagram form, rather than indetail, in order to avoid obscuring the present disclosure.

All the features disclosed in this specification, (including anyaccompanying claims, abstract, and drawings) may be replaced byalternative features serving the same, equivalent or similar purpose,unless expressly stated otherwise. Thus, unless expressly statedotherwise, each feature disclosed is one example only of a genericseries of equivalent or similar features.

Furthermore, any element in a claim that does not explicitly state“means for” performing a specified function, or “step for” performing aspecific function, is not to be interpreted as a “means” or “step”clause as specified in 35 U.S.C. Section 112, Paragraph f. Inparticular, the use of “step of” or “act of” in the Claims herein is notintended to invoke the provisions of 35 U.S.C. 112, Paragraph f.

Please note, if used, the labels left, right, front, back, top, bottom,forward, reverse, clockwise and counter clockwise have been used forconvenience purposes only and are not intended to imply any particularfixed direction. Instead, they are used to reflect relative locationsand/or directions between various portions of an object.

Definitions

As used here, the phrase “electrochemical cell,” refers to, for example,a “battery cell” and includes a positive electrode, a negativeelectrode, and an electrolyte therebetween which conducts ions (e.g.,Li) but electrically insulates the positive and negative electrodes. Insome embodiments, a battery may include multiple positive electrodesand/or multiple negative electrodes enclosed in one container.

As used here, the phrase “positive electrode,” refers to the electrodein a secondary battery towards which positive ions, e.g., Li⁺, conduct,flow or move during discharge of the battery. As used herein, the phrase“negative electrode” refers to the electrode in a secondary battery fromwhere positive ions, e.g., Li⁺, flow or move during discharge of thebattery. In a battery comprised of a Li-metal electrode and a conversionchemistry, intercalation chemistry, or combinationconversion/intercalation chemistry-including electrode (i.e., cathodeactive material; e.g., NiF_(x), NCA, LiNi_(x)Mn_(y)Co_(z)O₂[NMC] orLiNi_(x)Al_(y)Co_(z)O₂[NCA], wherein x+y+z=1), the electrode having theconversion chemistry, intercalation chemistry, or combinationconversion/intercalation chemistry material is referred to as thepositive electrode. In some common usages, cathode is used in place ofpositive electrode, and anode is used in place of negative electrode.When a Li-secondary battery is charged, Li ions move from the positiveelectrode (e.g., NiF_(x), NMC, NCA) towards the negative electrode(e.g., Li-metal). When a Li-secondary battery is discharged, Li ionsmove towards the positive electrode and from the negative electrode.

As used herein, a “binder” refers to a material that assists in theadhesion of another material. For example, as used herein, polyvinylbutyral is a binder because it is useful for adhering garnet materials.Other binders include polycarbonates. Other binders may includepolymethylmethacrylates. These examples of binders are not limiting asto the entire scope of binders contemplated here but merely serve asexamples. Binders useful in the present disclosure include, but are notlimited to, polypropylene (PP), atactic polypropylene (aPP), isotactivepolypropylene (iPP), ethylene propylene rubber (EPR), ethylene pentenecopolymer (EPC), polyisobutylene (PIB), styrene butadiene rubber (SBR),polyolefins, polyethylene-co-poly-1-octene (PE-co-PO),PE-co-poly(methylene cyclopentane) (PE-co-PMCP), polymethyl-methacrylate (and other acrylics), acrylic, polyvinylacetacetalresin, polyvinylbutylal resin, PVB, polyvinyl acetal resin, stereoblockpolypropylenes, polypropylene polymethylpentene copolymer, polyethyleneoxide (PEO), PEO block copolymers, silicone, and the like.

As used here, the phrase “composite electrolyte,” refers to anelectrolyte, as referenced above, having at least two components, e.g.,an inorganic solid state electrolyte and a polymer bonded to theelectrolyte, adhered to the electrolyte, or uniformly mixed with theelectrolyte. In certain examples, the at least two components include apolymer, or organic binder, and an inorganic solid state electrolyte. Acomposite electrolyte may include an inorganic solid state electrolyteand a polymer, bonded thereto, adhered thereto, adsorbed there onto, ormixed therewith. A composite electrolyte may include an inorganic solidstate electrolyte and a polymer, bonded thereto, adhered thereto,adsorbed there onto, or mixed therewith. A composite electrolyte mayinclude an inorganic solid state electrolyte and the chemical precursorsto a polymer which bonds to, adheres to, adsorbs onto, or mix withand/or entangles with, once polymerized, the inorganic solid stateelectrolyte. A composite electrolyte may include an inorganic solidstate electrolyte and monomers which can be polymerized to form apolymer which bonds to, adheres to, adsorbs onto, or mix with and/orentangles with, once polymerized, the inorganic solid state electrolyte.For example, a composite electrolyte may include a solid stateelectrolyte, e.g., a sulfide-including electrolyte, and epoxide monomersor epoxide-including polymers. In such an example, the epoxide monomerscan be polymerized by polymerization techniques known in the art, suchas but not limited light-initiated or chemical-initiated,polymerization.

As used here, the phrase “inorganic solid state electrolyte,” refers toa material which does not include carbon and which conducts atomic ions(e.g., Li) but does not conduct electrons. An inorganic solid stateelectrolyte is a solid material suitable for electrically isolating thepositive and negative electrodes of a lithium secondary battery whilealso providing a conduction pathway for lithium ions. Example inorganicsolid state electrolytes include oxide electrolytes and sulfideelectrolytes, which are further defined below. Non-limiting examplesulfide electrolytes are found, for example, in U.S. Pat. No. 9,172,114,which issued Oct. 27, 2015, and also in U.S. Provisional PatentApplication Publication No. 62/321,428, filed Apr. 12, 2016.Non-limiting example oxide electrolytes are found, for example, in USPatent Application Publication No. 2015-0200420 A1, which published Jul.16, 2015.

As used here, the phrase “directly contacts,” refers to thejuxtaposition of two materials such that the two materials contact eachother sufficiently to conduct either an ionic or electronic current. Asused herein, “direct contact” refers to two materials in physicalcontact with each other and which do not have any third materialpositioned between the two materials which are in direct contact.

As used herein, the phrase “inorganic material embedded in an organicmaterial,” refers to an inorganic material which is surrounded by andfixed to the organic material. In different examples, the organicmaterial may be bonded to or adsorbed onto the inorganic material; orthe organic material may entangle with surface attached species whichare present on the inorganic material. In yet other examples, theorganic material may completely surround the inorganic material. In yetother examples, the organic material may be molded around the inorganicmaterial. In all of these examples, the inorganic material is fixedwithin the organic material, or surrounded by the organic material, suchthe inorganic material cannot physically move without breaking bonds toor within the organic material. The composites having a fixed inorganicmaterial in an organic material, described herein, may have uniquephysical properties (e.g., fracture strength) which are not present ineither the inorganic or organic materials individually.

As used herein, the phrase “fracture strength,” refers to a measure offorce required to break a material, e.g., a composite electrolyte, byinducing a crack or fracture therein. Fracture strength values recitedherein were measured using the ring on ring test in Example 19. Thering-on-ring test is a measure of equibiaxial flexural strength and maybe measured as specified in the ASTM C1499-09 standard. It is measuredat ambient temperature.

As used herein the term “polyamine,” refers to a molecule that includesmore than one amino functional group on a given molecule. For example,diethylenetriamine (DETA) includes three amino functional groups on theDETA molecule. DETA is therefore a polyamine in so far as the term isused herein.

As used herein the term “aspect ratio,” refers to a the ratio of thelength to width of a particle. Aspect ratio is measured by focused-ionbeam cross-section scanning electron microscopy. In the SEM image of aparticle, the aspect ratio is calculated by determining the best-fitellipse for the major axis)/(minor axis) of the best-fit ellipse.

As used here, the phrase “lithium-stuffed garnet electrolyte,” refers tooxides that are characterized by a crystal structure related to a garnetcrystal structure. Lithium-stuffed garnets include compounds having theformula Li_(A)La_(B)M′_(c)M″_(D)Zr_(E)O_(F),Li_(A)La_(B)M′_(C)M″_(D)Ta_(E)O_(F), orLi_(A)La_(B)M′_(C)M″_(D)Nb_(E)O_(F), wherein 4<A<8.5, 1.5<B<4, 0≤C≤2,0≤D≤2; 0≤E<2, 10<F<13, and M″ and M″ are each, independently in eachinstance selected from Al, Mo, W, Nb, Sb, Ca, Ba, Sr, Ce, Hf, Rb, or Ta,or Li_(a)La_(b)Zr_(c)Al_(d)Me″_(e)O_(f), wherein 5<a<7.7; 2<b<4;0<c≤2.5; 0≤d<2; 0≤e<2, 10<f<13 and Me″ is a metal selected from Nb, Ta,V, W, Mo, or Sb and as described herein. Garnets, as used herein, alsoinclude those garnets described above that are doped with Al₂O₃.Garnets, as used herein, also include those garnets described above thatare doped so that Al³⁺ substitutes for Li⁺. As used herein,lithium-stuffed garnets, and garnets, generally, include, but are notlimited to, Li_(7.0)La₃(Zr_(t1)+Nb_(t2)+Ta_(t3))O₁₂+0.35Al₂O₃; wherein(t1+t2+t3=subscript 2) so that the La:(Zr/Nb/Ta) ratio is 3:2. Also,garnet used herein includes, but is not limited to,Li_(x)La₃Zr₂O₁₂+yAl₂O₃, wherein x ranges from 5.5 to 9; and y rangesfrom 0 to 1. In some examples x is 7 and y is 1.0. In some examples x is7 and y is 0.35. In some examples x is 7 and y is 0.7. In some examplesx is 7 and y is 0.4. Also, garnets as used herein include, but are notlimited to, Li_(x)La₃Zr₂O₁₂+yAl₂O₃. Non-limiting example lithium-stuffedgarnet electrolytes are found, for example, in US Patent ApplicationPublication No. 2015-0200420 A1, which published Jul. 16, 2015.

As used herein, garnet does not include YAG-garnets (i.e., yttriumaluminum garnets, or, e.g., Y₃Al₅O₁₂). As used herein, garnet does notinclude silicate-based garnets such as pyrope, almandine, spessartine,grossular, hessonite, or cinnamon-stone, tsavorite, uvarovite andandradite and the solid solutions pyrope-almandine-spessarite anduvarovite-grossular-andradite. Garnets herein do not includenesosilicates having the general formula X₃Y₂(SiO₄)₃ wherein X is Ca,Mg, Fe, and, or, Mn; and Y is Al, Fe, and, or, Cr.

As used herein the term “porous,” refers to a material that includespores, e.g., nanopores, mesopores, or micropores.

As used herein the term “infiltrated,” refers to the state wherein onematerial passes into another material, or when one material is caused tojoin another material. For example, if a porous Garnet is infiltratedwith carbon, this refers to the process whereby carbon is caused to passinto and, or, intimately mix with the porous Garnet.

As used here, the phrase “sulfide electrolyte,” refers to an inorganicsolid state material that conducts Li⁺ ions but is substantiallyelectronically insulating. Example LXPS materials are found, forexample, in International PCT Patent Application No. PCT/US14/38283,filed May 15, 2014, and entitled SOLID STATE CATHOLYTE OR ELECTROLYTEFOR BATTERY USING Li_(A)MP_(B)S_(C) (M=Si, Ge, AND/OR Sn); also, U.S.Pat. No. 8,697,292 to Kanno, et al, the contents of which areincorporated by reference in their entirety.

As used here, the phrase “sulfide electrolyte,” includes, but are notlimited to, LSS, LTS, LXPS, LXPSO, where X is Si, Ge, Sn, As, Al, LATS,also Li-stuffed garnets, or combinations thereof, and the like, S is S,Si, or combinations thereof, T is Sn.

As used here, “LSS” refers to lithium silicon sulfide which can bedescribed as Li₂S—SiS₂, Li—SiS₂, Li—S—Si, and/or a catholyte consistingessentially of Li, S, and Si. LSS refers to an electrolyte materialcharacterized by the formula Li_(x)Si_(y)S_(z) where 0.33≤x≤0.5,0.1≤y≤0.2, 0.4≤z≤0.55, and it may include up to 10 atomic % oxygen. LSSalso refers to an electrolyte material comprising Li, Si, and S. In someexamples, LSS is a mixture of Li₂S and SiS₂. In some examples, the ratioof Li₂S:SiS₂ is 90:10, 85:15, 80:20, 75:25, 70:30, 2:1, 65:35, 60:40,55:45, or 50:50 molar ratio. LSS may be doped with compounds such asLi_(x)PO_(y), Li_(x)BO_(y), Li₄SiO₄, Li₃MO₄, Li₃MO₃, PSX, and/or lithiumhalides such as, but not limited to, LiI, LiCl, LiF, or LiBr, wherein0<x≤5 and 0<y≤5.

As used here, “LTS” refers to a lithium tin sulfide compound which canbe described as Li₂S—SnS₂, Li₂S—SnS, Li—S—Sn, and/or a catholyteconsisting essentially of Li, S, and Sn. The composition may beLi_(x)Sn_(y)S_(z) where 0.25≤x≤0.65, 0.05≤y≤0.2, and 0.25≤z≤0.65. Insome examples, LTS is a mixture of Li₂S and SnS₂ in the ratio of 80:20,75:25, 70:30, 2:1, or 1:1 molar ratio. LTS may include up to 10 atomic %oxygen. LTS may be doped with Bi, Sb, As, P, B, Al, Ge, Ga, and/or In.As used herein, “LATS” refers to LTS, as used above, and furthercomprising Arsenic (As).

As used here, “LXPS” refers to a material characterized by the formulaLi_(a)MP_(b)S_(c), where M is Si, Ge, Sn, and/or Al, and where 2≤a≤8,0.5≤b≤2.5, 4≤c≤12. “LSPS” refers to an electrolyte materialcharacterized by the formula L_(a)SiP_(b)S_(c), where 2≤a≤8, 0.5≤b≤2.5,4≤c≤12. LSPS refers to an electrolyte material characterized by theformula L_(a)SiP_(b)S_(c), wherein, where 2≤a≤8, 0.5≤b≤2.5, 4≤c≤12, d<3.Exemplary LXPS materials are found, for example, in International PatentApplication No. PCT/US2014/038283, filed May 16, 2014, and entitledSOLID STATE CATHOLYTE OR ELECTROLYTE FOR BATTERY USING LI_(A)MP_(B)S_(C)(M=Si, Ge, AND/OR Sn), which is incorporated by reference herein in itsentirety. When M is Sn and Si—both are present—the LXPS material isreferred to as LSTPS. As used herein, “LSTPSO,” refers to LSTPS that isdoped with, or has, O present. In some examples, “LSTPSO,” is a LSTPSmaterial with an oxygen content between 0.01 and 10 atomic %. “LSPS,”refers to an electrolyte material having Li, Si, P, and S chemicalconstituents. As used herein “LSTPS,” refers to an electrolyte materialhaving Li, Si, P, Sn, and S chemical constituents. As used herein,“LSPSO,” refers to LSPS that is doped with, or has, O present. In someexamples, “LSPSO,” is a LSPS material with an oxygen content between0.01 and 10 atomic %. As used herein, “LATP,” refers to an electrolytematerial having Li, As, Sn, and P chemical constituents. As used herein“LAGP,” refers to an electrolyte material having Li, As, Ge, and Pchemical constituents. As used herein, “LXPSO” refers to a catholytematerial characterized by the formula Li_(a)MP_(b)S_(c)O_(d), where M isSi, Ge, Sn, and/or Al, and where 2≤a≤8, 0.5≤b≤2.5, 4≤c≤12, d<3. LXPSOrefers to LXPS, as defined above, and having oxygen doping at from 0.1to about 10 atomic %. LPSO refers to LPS, as defined above, and havingoxygen doping at from 0.1 to about 10 atomic %.

As used here, “LPS,” refers to an electrolyte having Li, P, and Schemical constituents. As used herein, “LPSO,” refers to LPS that isdoped with or has O present. In some examples, “LPSO,” is a LPS materialwith an oxygen content between 0.01 and 10 atomic %. LPS refers to anelectrolyte material that can be characterized by the formulaLi_(x)P_(y)S_(z) where 0.33≤x≤0.67, 0.07≤y≤0.2 and 0.4≤z≤0.55. LPS alsorefers to an electrolyte characterized by a product formed from amixture of Li₂S:P₂S₅ wherein the molar ratio is 10:1, 9:1, 8:1, 7:1, 6:15:1, 4:1, 3:1, 7:3, 2:1, or 1:1. LPS also refers to an electrolytecharacterized by a product formed from a mixture of Li₂S:P₂S₅ whereinthe reactant or precursor amount of Li₂S is 95 atomic % and P₂S₅ is 5atomic %. LPS also refers to an electrolyte characterized by a productformed from a mixture of Li₂S:P₂S₅ wherein the reactant or precursoramount of Li₂S is 90 atomic % and P₂S₅ is 10 atomic %. LPS also refersto an electrolyte characterized by a product formed from a mixture ofLi₂S:P₂S₅ wherein the reactant or precursor amount of Li₂S is 85 atomic% and P₂S₅ is 15 atomic %. LPS also refers to an electrolytecharacterized by a product formed from a mixture of Li₂S:P₂S₅ whereinthe reactant or precursor amount of Li₂S is 80 atomic % and P₂S₅ is 20atomic %. LPS also refers to an electrolyte characterized by a productformed from a mixture of Li₂S:P₂S₅ wherein the reactant or precursoramount of Li₂S is 75 atomic % and P₂S₅ is 25 atomic %. LPS also refersto an electrolyte characterized by a product formed from a mixture ofLi₂S:P₂S₅ wherein the reactant or precursor amount of Li₂S is 70 atomic% and P₂S₅ is 30 atomic %. LPS also refers to an electrolytecharacterized by a product formed from a mixture of Li₂S:P₂S₅ whereinthe reactant or precursor amount of Li₂S is 65 atomic % and P₂S₅ is 35atomic %. LPS also refers to an electrolyte characterized by a productformed from a mixture of Li₂S:P₂S₅ wherein the reactant or precursoramount of Li₂S is 60 atomic % and P₂S₅ is 40 atomic 0.

As used here, LPSO refers to an electrolyte material characterized bythe formula Li_(x)P_(y)S_(z)O, where 0.33≤x≤0.67, 0.07≤y≤0.2,0.4≤z≤0.55, 0≤w≤0.15. Also, LPSO refers to LPS, as defined above, thatincludes an oxygen content of from 0.01 to 10 atomic %. In someexamples, the oxygen content is 1 atomic %. In other examples, theoxygen content is 2 atomic %. In some other examples, the oxygen contentis 3 atomic %. In some examples, the oxygen content is 4 atomic %. Inother examples, the oxygen content is 5 atomic %. In some otherexamples, the oxygen content is 6 atomic %. In some examples, the oxygencontent is 7 atomic %. In other examples, the oxygen content is 8 atomic%. In some other examples, the oxygen content is 9 atomic %. In someexamples, the oxygen content is 10 atomic %.

As used here, the term “necked,” refers to a particle to particleconnectivity for particles in a polymer or solvent matrix. As neckedelectrolyte particles, these particle are in sufficient contact as toprovide an ion conduction path through the particles and a polymer orsolvent and by way of the particle to particle contacts. Necked caninclude particles that are sintered together, face sharing, edgesharing, corner sharing, or otherwise bonded together and which form apercolation network when composited with a polymer or solvent.

As used here, the phrase “sulfide based electrolytes,” refers toelectrolytes that include inorganic materials containing S which conductions (e.g., Li) and which are suitable for electrically insulating thepositive and negative electrodes of an electrochemical cell (e.g.,secondary battery). Exemplary sulfide based electrolytes are set forthin International Patent Application PCT Patent Application No.PCT/US14/38283, SOLID STATE CATHOLYTE OR ELECTROLYTE FOR BATTERY USINGLI_(A)MP_(B)S_(C) (M=SI, GE, AND/OR SN), filed May 15, 2014, andpublished as WO 2014/186634, on Nov. 20, 2014, which is incorporated byreference herein in its entirety.

As used here, examples of the materials in International PatentApplication PCT Patent Application Nos. PCT/US2014/059575 andPCT/US2014/059578, GARNET MATERIALS FOR LI SECONDARY BATTERIES ANDMETHODS OF MAKING AND USING GARNET MATERIALS, filed Oct. 7, 2014, whichis incorporated by reference herein in its entirety, are suitable foruse as the inorganic solid state electrolytes described herein, also asthe oxide based electrolytes, described herein, and also as the garnetelectrolytes, described herein.

As used here, the term “electrolyte,” refers to a material that allowsions, e.g., Li⁺, to migrate therethrough but which does not allowelectrons to conduct therethrough. Electrolytes are useful forelectrically isolating the cathode and anodes of a secondary batterywhile allowing ions, e.g., Li+, to transmit through the electrolyte.Solid electrolytes, in particular, rely on ion hopping through rigidstructures. Solid electrolytes may be also referred to as fast ionconductors or super-ionic conductors. Solid electrolytes may be alsoused for electrically insulating the positive and negative electrodes ofa cell while allowing for the conduction of ions, e.g., Li+, through theelectrolyte. In this case, a solid electrolyte layer may be alsoreferred to as a solid electrolyte separator.

As used herein, the phrase “film thickness” refers to the distance, ormedian measured distance, between the top and bottom faces of a film. Asused herein, the top and bottom faces refer to the sides of the filmhaving the largest surface area.

As used herein, the term “grains” refers to domains of material withinthe bulk of a material that have a physical boundary which distinguishesthe grain from the rest of the material. For example, in some materialsboth crystalline and amorphous components of a material, often havingthe same chemical composition, are distinguished from each other by theboundary between the crystalline component and the amorphous component.The approximate diameter of the boundaries of a crystalline component,or of an amorphous component, is referred herein as the grain size.

As used herein, the phrase “d₅₀ diameter” refers to the median size, ina distribution of sizes, measured by microscopy techniques or otherparticle size analysis techniques, such as, but not limited to, scanningelectron microscopy or dynamic light scattering. D₅₀ includes thecharacteristic dimension at which 50% of the particles are smaller thanthe recited size.

As used herein the phrase “casting a film,” refers to the process ofdelivering or transferring a liquid or a slurry into a mold, or onto asubstrate, such that the liquid or the slurry forms, or is formed into,a film. Casting may be done via doctor blade, Meyer rod, comma coater,gravure coater, microgravure, reverse comma coater, slot dye, slipand/or tape casting, and other methods known to those skilled in theart.

As used herein, the phrase “slot casting,” refers to a depositionprocess whereby a substrate is coated, or deposited, with a solution,liquid, slurry, or the like by flowing the solution, liquid, slurry, orthe like, through a slot or mold of fixed dimensions that is placedadjacent to, in contact with, or onto the substrate onto which thedeposition or coating occurs. In some examples, slot casting includes aslot opening of about 1 to 100 μm.

As used herein, the phrase “dip casting” or “dip coating” refers to adeposition process whereby substrate is coated, or deposited, with asolution, liquid, slurry, or the like, by moving the substrate into andout of the solution, liquid, slurry, or the like, often in a verticalfashion.

As used herein, the term “laminating” refers to the process ofsequentially depositing a layer of one precursor specie, e.g., a lithiumprecursor specie, onto a deposition substrate and then subsequentlydepositing an additional layer onto an already deposited layer using asecond precursor specie, e.g., a transition metal precursor specie. Thislaminating process can be repeated to build up several layers ofdeposited vapor phases. As used herein, the term “laminating” alsorefers to the process whereby a layer comprising an electrode, e.g.,positive electrode or cathode active material comprising layer, iscontacted to a layer comprising another material, e.g., garnetelectrolyte. The laminating process may include a reaction or use of abinder which adheres of physically maintains the contact between thelayers which are laminated.

As used herein, the phrase “green film” refers to an unsintered filmincluding at least one member selected from garnet materials, precursorsto garnet materials, binder, solvent, carbon, dispersant, orcombinations thereof.

As used herein the term “making,” refers to the process or method offorming or causing to form the object that is made. For example, makingan energy storage electrode includes the process, process steps, ormethod of causing the electrode of an energy storage device to beformed. The end result of the steps constituting the making of theenergy storage electrode is the production of a material that isfunctional as an electrode.

As used herein, the phrase “providing” refers to the provision of,generation or, presentation of, or delivery of that which is provided.

As used herein, the phrases “garnet precursor chemicals,” “chemicalprecursor to a Garnet-type electrolyte,” or “garnet chemical precursors”refers to chemicals which react to form a lithium stuffed garnetmaterial described herein. These chemical precursors include, but arenot limited to, lithium hydroxide (e.g., LiOH), lithium oxide (e.g.,Li₂O), lithium carbonate (e.g., LiCO₃), zirconium oxide (e.g., ZrO₂),lanthanum oxide (e.g., La₂O₃), aluminum oxide (e.g., Al₂O₃), aluminum(e.g., Al), aluminum nitrate (e.g., AlNO₃), aluminum nitratenonahydrate, niobium oxide (e.g., Nb₂O₅), and tantalum oxide (e.g.,Ta₂O₅).

As used herein the phrase “garnet-type electrolyte,” refers to anelectrolyte that includes a garnet or lithium stuffed garnet materialdescribed herein as the ionic conductor.

As used herein the phrase “antiperovskite” refers to an electrolytecharacterized by the antiperovskite crystal structure. Exemplaryantiperovskites are found, for example, in U.S. patent application Ser.No. 13/777,602, filed Feb. 26, 2013. Antiperovskites include but are notlimited to Li₃OBr or Li₃OCl.

As used herein, the phrase “subscripts and molar coefficients in theempirical formulas are based on the quantities of raw materialsinitially batched to make the described examples” means the subscripts,(e.g., 7, 3, 2, 12 in Li₇La₃Zr₂O₁₂ and the coefficient 0.35 in0.35Al₂O₃) refer to the respective elemental ratios in the chemicalprecursors (e.g., LiOH, La₂O₃, ZrO₂, Al₂O₃) used to prepare a givenmaterial, (e.g., Li₇La₃Zr₂O₁₂ 0.35Al₂O₃). As used here, the phrase“characterized by the formula,” refers to a molar ratio of constituentatoms either as batched during the process for making that characterizedmaterial or as empirically determined.

As used herein, the term “back-fill,” refers to a process whereby voidspaces, textured spaces, porosity spaces, or available surface area of asintered inorganic electrolyte is covered, contacted with, orinfiltrated by a species, such as but not limited to a polymer or abinder. The covering, contacting, or infiltrating of the sinteredelectrolyte with a polymer may, in some examples, be assisted with theuse of a solvent, or combination of solvents, and, or, dispersants,surfactants, or combinations thereof. In some examples, backfillingincludes a step of infiltrating, covering or contacting the sinteredelectrolyte with a polymer and optionally a solvent, dispersant,surfactant, or combination thereof, followed by a step in which thesintered electrolyte having a back-filled polymer therein is dried toremove the solvent.

As used herein the term “solvent,” refers to a liquid that is suitablefor dissolving or solvating a component or material described herein.For example, a solvent includes a liquid, e.g., toluene, which issuitable for dissolving a component, e.g., the binder, used in thegarnet sintering process.

As used herein the phrase “removing a solvent,” refers to the processwhereby a solvent is extracted or separated from the components ormaterials set forth herein. Removing a solvent includes, but is notlimited to, evaporating a solvent. Removing a solvent includes, but isnot limited to, using a vacuum or a reduced pressure to drive off asolvent from a mixture, e.g., an unsintered thin film. In some examples,a thin film that includes a binder and a solvent is heated or alsooptionally placed in a vacuum or reduced atmosphere environment in orderto evaporate the solvent to leave the binder, which was solvated, in thethin film after the solvent is removed.

As used herein the phrase “sintering the film,” refers to a processwhereby a thin film, as described herein, is densified (made denser, ormade with a reduced porosity) through the use of heat sintering or fieldassisted sintering. Sintering includes the process of forming a solidmass of material by heat and/or pressure without melting it to the pointof complete liquification.

Composites

Set forth herein are a variety of composite electrolytes.

In some examples, set forth herein is an electrolyte including aninorganic material embedded in an organic material. In some examples,the electrolyte has a fracture strength of greater than 5 MPa and lessthan 250 MPa. In certain examples, the organic material does not conductLi⁺ ions.

In some examples herein, the organic material in the compositeelectrolyte is bonded to, adsorbed on, molded around, or entangled withthe surface of the inorganic material, a surface attached species on thesurface of the inorganic material, or an inorganic material particle.

In some examples, the organic material is bonded to the surface of theinorganic material. In certain examples, the organic material is bondedto the surface of the inorganic material by covalent, ionic,electrostatic, or van Der Waals bonds. In certain other examples, theorganic material is bonded to the surface of the inorganic material bycovalent, ionic, electrostatic, or van Der Waals bonds and has a lithiumion conductivity of less than 1e-8S/cm at 80° C. In yet other examples,the organic material is bonded to the surface of the inorganic materialby non-covalent bonds.

In some examples, the organic material includes a functional groupselected from a carboxylic acid, an ester, an amide, an amine, a silane,sulfonic acid, a phosphate, a phosphine oxide, a phosphoric acid, analkoxide, a nitrile, a thioether, thiol, and combinations thereof. Insome examples, the organic material includes a carboxylic acid. In someexamples, the organic material includes an ester. In some examples, theorganic material includes an amine. In some examples, the organicmaterial includes a silane. In some examples, the organic materialincludes a sulfonic acid. In some examples, the organic materialincludes a phosphate. In some examples, the organic material includes aphosphine. In some examples, the organic material includes an epoxide.In some examples, the organic material includes a nitrile. In someexamples, the organic material includes a thiol. In some examples, theorganic material includes a thio-ether.

In certain examples, the inorganic material includes a surface specieswhich reacts with a functional group selected from an epoxide, acarboxylic acid, an ester, an amide, an amine, a sulfonic acid, aphosphate, a phosphine oxide, a phosphoric acid, an alkoxides, anitrile, a thioether, thiol, and combinations thereof.

In some of the composite electrolytes disclosed herein, the surfacespecies on the inorganic material is selected from a thiol, a hydroxide,a sulfide, an oxide, and a combination thereof. In other examples, thesurface specie is a monomer, oligomer, or polymer attached to thesurface of the inorganic material.

In some of the composite electrolytes disclosed herein, the inorganicmaterial comprises a surface species which interacts with a functionalgroup selected from an epoxide, carboxylic acid, an ester, an amide, anamine, a sulfonic acid, a phosphate, a phosphine oxide, a phosphoricacid, an alkoxides, a nitrile, a thioether, thiol, and combinationsthereof.

In some of the composite electrolytes disclosed herein, the organicmaterial has polar functional groups.

In some of the composite electrolytes disclosed herein, the organicmaterial is absorbed within the inorganic material.

In some of the composite electrolytes disclosed herein, the surface ofthe inorganic material is roughened and the organic material is adsorbedwithin the roughened surface of the inorganic material.

In some of the composite electrolytes disclosed herein, the organicmaterial is molded around the inorganic material.

In some of the composite electrolytes disclosed herein, the organicmaterial is polymerized around the inorganic material.

In some of the composite electrolytes disclosed herein, the organicmaterial is entangled with the inorganic material.

In some of the composite electrolytes disclosed herein, the organicmaterial is entangled with a surface species which is present on theinorganic material.

In some examples herein, the inorganic material comprisesnecked-particles of inorganic material.

In any of the examples herein, the electrolyte may be a solid.

In some of the composite electrolytes disclosed herein, the electrolyteis a solid thin film having a thickness between 1 nm and 100 μm. In someof the composite electrolytes disclosed herein, the electrolyte is asolid thin film having a thickness between 10, 20, 30, 40, 50, 60, 70,80, or 90 μm. In some of the composite electrolytes disclosed herein,the electrolyte is a solid thin film having a thickness between 500 μmto 800 μm.

In some of the composite electrolytes disclosed herein, the inorganicmaterial is a solid state electrolyte.

In some of the composite electrolytes disclosed herein, the inorganicmaterial is a solid state electrolyte selected from a lithium-stuffedgarnet oxide, an antiperovskite oxide, a lithium borohydride, a lithiumiodide-containing material and a lithium sulfide-containing material. Insome of the composite electrolytes disclosed herein, the inorganicmaterial is a solid state electrolyte selected from a lithium-stuffedgarnet oxide. In some of the composite electrolytes disclosed herein,the inorganic material is a solid state electrolyte selected from anantiperovskite. In some of the composite electrolytes disclosed herein,the inorganic material is a solid state electrolyte selected fromlithium borohydride. In some of the composite electrolytes disclosedherein, the inorganic material is a solid state electrolyte selectedfrom a lithium iodide-containing material. In some of the compositeelectrolytes disclosed herein, the inorganic material is a solid stateelectrolyte selected from a lithium sulfide-containing material.

In some examples, the inorganic material is a solid state electrolyte ofa lithium-stuffed garnet oxide characterized by the formulaLi_(u)La_(v)Zr_(x)O_(y).zAl₂O₃, wherein u is a rational number from 4 to10; v is a rational number from 2 to 4; x is a rational number from 1 to3; y is a rational number from 10 to 14; and z is a rational number from0 to 1; wherein u, v, x, y, and z are selected so that thelithium-stuffed garnet oxide is charge neutral.

In some examples, the inorganic material in a composite electrolyte is alithium-stuffed garnet oxide characterized by the formulaLi_(u)La₃Zr₂O₁₂.zAl₂O₃, wherein 4≤u≤10 and 0<z≤1

In some examples, the inorganic material in a composite electrolyte is alithium-stuffed garnet oxide is characterized by the formulaLi_(6.75-7.1)La₃Zr₂O₁₂.0.5Al₂O₃ or Li_(6.4-7.7)La₃Zr₂O₁₂.0.11Al₂O₃.

In some examples, the inorganic material in a composite electrolyte is asolid state electrolyte selected from a lithium sulfide characterized byone of the following Formula

-   -   Li_(a)Si_(b)Sn_(c)P_(d)S_(e)O_(f), wherein 2≤a≤8, b+c=1,        0.5≤d≤2.5, 4≤e≤12, and 0<f≤10;    -   Li_(g)As_(h)Sn_(j)S_(k)O_(l), wherein 2≤g≤6, 0≤h≤1, 0≤j≤1,        2≤k≤6, and 0≤l≤10;    -   Li_(m)P_(n)S_(p)I_(q), wherein 2≤m≤6, 0≤n≤1, 0≤p≤1, 2≤q≤6;    -   a mixture of (Li₂S):(P₂S₅) having a molar ratio from about 10:1        to about 6:4 and LiI, wherein the ratio of [(Li₂S):(P₂S₅)]:LiI        is from 95:5 to 50:50;    -   a mixture of LiI and Al₂O₃;    -   Li₃N;    -   LPS+X, wherein X is selected from Cl, I, or Br;    -   vLi₂S+wP₂S₅+yLiX;    -   vLi₂S+wSiS₂+yLiX;    -   vLi₂S+wB₂S₃+yLiX;    -   a mixture of LiBH₄ and LiX wherein X is selected from Cl, I, or        Br; or    -   vLiBH₄+wLiX+yLiNH₂, wherein X is selected from Cl, I, or Br; and    -   wherein coefficients v, w, and y are rational numbers from 0 to        1.

In some examples, the inorganic material in a composite electrolyte is asolid state electrolyte selected from a lithium sulfide characterized byLi₁₀Si_(0.5)Sn_(0.5)P₂Si₂ and Li₇₄P_(1.6)S_(7.2)I.

In some examples, the inorganic material in a composite electrolyte is asolid state electrolyte selected from a lithium sulfide characterized byLi₇₄P_(1.6)S_(7.2)I.

In some examples, the composite electrolyte herein includes an organicmaterial which is a polymer. In some examples, the organic material is apolymer selected from the group consisting of polyolefins, naturalrubbers, synthetic rubbers, polybutadiene, polyisoprene, epoxidizednatural rubber, polyisobutylene, polypropylene oxide, polyacrylates,polymethacrylates, polyesters, polyvinyl esters, polyurethanes, styrenicpolymers, epoxy resins, epoxy polymers, poly(bisphenolA-co-epichlorohydrin), vinyl polymers, polyvinyl halides, polyvinylalcohol, polyethyleneimine, poly(maleic anhydride), silicone polymers,siloxane polymers, polyacrylonitrile, polyacrylamide, polychloroprene,polyvinylidene fluoride, polyvinyl pyrrolidone, polyepichlorohydrin, andblends or copolymers thereof. In certain examples, the polymer ispolyolefins. In certain examples, the polymer is natural rubbers. Incertain examples, the polymer is synthetic rubbers. In certain examples,the polymer is polybutadiene. In certain examples, the polymer ispolyisoprene. In certain examples, the polymer is epoxidized naturalrubber. In certain examples, the polymer is polyisobutylene. In certainexamples, the polymer is polypropylene oxide. In certain examples, thepolymer is polyacrylates. In certain examples, the polymer ispolymethacrylates. In certain examples, the polymer is polyesters. Incertain examples, the polymer is polyvinyl esters. In certain examples,the polymer is polyurethanes. In certain examples, the polymer isstyrenic polymers. In certain examples, the polymer is epoxy resins. Incertain examples, the polymer is epoxy polymers. In certain examples,the polymer is poly(bisphenol A-co-epichlorohydrin). In certainexamples, the polymer is vinyl polymers. In certain examples, thepolymer is polyvinyl halides. In certain examples, the polymer ispolyvinyl alcohol. In certain examples, the polymer ispolyethyleneimine. In certain examples, the polymer is poly(maleicanhydride). In certain examples, the polymer is silicone polymers. Incertain examples, the polymer is siloxane polymers. In certain examples,the polymer is polyacrylonitrile. In certain examples, the polymer ispolyacrylamide. In certain examples, the polymer is polychloroprene. Incertain examples, the polymer is polyvinylidene fluoride. In certainexamples, the polymer is polyvinyl pyrrolidone. In certain examples, thepolymer is polyepichlorohydrin. In some examples, molecular weight ofthe polymer is greater than 50,000 g/mol.

In some examples, the polymer is preformed and selected from the groupconsisting of polypropylene, polyethylene, polybutadiene, polyisoprene,epoxidized natural rubber, poly(butadiene-co-acrylonitrile),polyethyleneimine, polydimethylsiloxane, and poly(ethylene-co-vinylacetate). In some examples, the molecular weight of the polymer isgreater than 50,000 g/mol.

In some examples, the organic material comprises one or morepolymerizable or crosslinkable members selected from the groupconsisting of vinyl esters, acrylates, methacrylates, styrenic monomers,vinyl-functionalized oligomers of polybutadiene, vinyl-functionalizedoligomers of polysiloxanes, and mixtures thereof.

In some examples, the organic material comprises one or morecrosslinkable members selected from the group consisting of diglycidylethers, epoxy resins, polyamines, and mixtures thereof.

In some examples, the organic material comprises one or morepolymerizable monomers selected from the group consisting of vinylesters, acrylates, methacrylates, styrenic monomers.

In some examples, the organic material comprises one or morecrosslinkable members selected from the group consisting of diglycidylethers, triglycidyl ethers, epoxy resins, polyamines.

In some examples, the organic material comprises one or morecrosslinkable oligomers selected from the group consisting ofvinyl-functionalized oligomers of polybutadiene, polysiloxanes, andmixtures thereof.

In some examples, the organic material comprises an epoxy resin.

In some examples, the organic material comprises an epoxy polymerprecursor selected from the group consisting of bisphenol A diglycidylether (DGEBA), poly(bisphenol A-co-epichlorohydrin) glycidyl end-cappedpolymers, diethylenetriamine (DETA) and derivatives thereof,tetraethylenepentamine and derivatives thereof, polyethyleneimine,carboxyl-terminated poly(butadiene-co-acrylonitrile), amine-terminatedpoly(butadiene-co-acrylonitrile), poly(propylene glycol) diglycidylether, poly(propylene glycol) bis(2-aminopropyl ether), and combinationsthereof.

In some examples, the organic material comprises an epoxy polymerprecursor selected from the group consisting of bisphenol A diglycidylether (DGEBA), poly(bisphenol A-co-epichlorohydrin) glycidyl end-cappedpolymers, diethylenetriamine (DETA) and derivatives thereof,tetraethylenepentamine and derivatives thereof, polyethyleneimine, andcombinations thereof.

In some examples, the composite further includes carboxyl-terminatedpoly(butadiene-co-acrylonitrile), amine-terminatedpoly(butadiene-co-acrylonitrile), poly(propylene glycol) diglycidylether, poly(propylene glycol) bis(2-aminopropyl ether), or combinationsthereof.

In some examples, the organic material comprises an epoxy polymer ofbisphenol A diglycidyl ether (DGEBA), diethylenetriamine (DETA), andamine-terminated poly(butadiene-co-acrylonitrile).

In some examples, the organic material comprises an epoxy polymer ofbisphenol A diglycidyl ether (DGEBA), diethylenetriamine (DETA), andpoly(propylene glycol) bis(2-aminopropyl ether).

In some examples, the composite includes a polymer of bisphenol Adiglycidyl ether and diethylenetriamine (DETA).

In some examples, the organic material comprises a polymer of bisphenolA diglycidyl ether and diethylenetriamine (DETA).

In some examples, the composite includes a polymer of bisphenol Adiglycidyl ether (DGEBA) and poly(propylene glycol) bis(2-aminopropylether).

In some examples, the organic material comprises a polymer of bisphenolA diglycidyl ether (DGEBA) and poly(propylene glycol) bis(2-aminopropylether).

In some examples, the poly(propylene glycol) bis(2-aminopropyl ether)has a molecular weight (g/mol) of about 100 to 50,000.

In some examples, the poly(propylene glycol) bis(2-aminopropyl ether)has a molecular weight (g/mol) of about 230 to 4000.

In some examples, the inorganic material has a silane attached to itssurface.

In some examples, the silane is selected from trichlorosilanes,trimethoxysilanes, and triethoxysilanes. In some examples, thetrichlorosilane is 3-methacryloxypropyltrichlorosilane. In someexamples, the trimethoxysilane is 3-acryloxypropyltrichlorosilane.

In some examples, the trichlorosilane is 7-octenyltrimethoxysilane.

In certain examples, herein, the inorganic material has a functionalgroup attached to its surface. In some examples, the functional group isselected from an anhydride, a disulfide, an epoxide, a carboxylic acidor an alkylhalide.

In some examples, the inorganic material is functionalized with silaneand wherein the organic material is a polymer selected frompolybutadiene.

In some examples, the electrolyte is directly in contact with a gelelectrolyte.

In some examples, the electrolyte has a fracture strength of greaterthan 5 MPa and less than 250 MPa. In certain examples, the electrolyteor composite electrolyte herein has a fracture strength of 50 MPa.

In certain examples, the electrolyte or composite electrolyte herein hasa fracture strength of 25 to 75 MPa.

Herein, the fracture strength is measured by a ring-on-ring test.

In some examples, the electrolyte or composite electrolyte, herein, doesnot form lithium metal dendrites when used in an electrochemical device,having a lithium metal negative electrode, and cycled at 1 mA/cm² Li⁺ion current density.

In some examples, the electrolyte or composite electrolyte, herein,prevents the formation of lithium metal dendrites when used in anelectrochemical device, having a lithium metal negative electrode, andcycled at 1 mA/cm² Li⁺ ion current density.

In some examples, the electrolyte or composite electrolyte, herein, doesnot form lithium metal dendrites for at least 20 cycles when used in anelectrochemical device, having a lithium metal negative electrode, andcycled at 1 mA/cm² Li⁺ ion current density at a temperature of 45° C.and a one-way charge of at least 2 mAh/cm² per half-cycle.

In some examples, the electrolyte or composite electrolyte, herein,prevents the formation of lithium metal dendrites for at least 20 cycleswhen used in an electrochemical device, having a lithium metal negativeelectrode, and cycled at 1 mA/cm² Li⁺ ion current density at atemperature of 45° C. and a one-way charge of at least 2 mAh/cm² perhalf-cycle.

In some examples, the electrolyte or composite electrolyte, herein, ispolished on its exterior surface.

In some examples, the electrolyte or composite electrolyte, herein, hasan ASR of between 0 and 20 Ω·cm² when measured at 45° C.

In some examples, the electrolyte or composite electrolyte, herein, ispolished on its exterior surface. In some examples, the electrolyte orcomposite electrolyte, herein, is chemically etched on its exteriorsurface. In some examples, the electrolyte or composite electrolyte,herein, is plasma-treated on its exterior surface.

In some examples, the electrolyte or composite electrolyte, herein, hasa total ASR of between 0 and 200 Ω·cm² at 45° C. In certain examples,the electrolyte has a total ASR of between 0 and 100 Ω·cm² at 45° C. Incertain other examples, the electrolyte has a total ASR of between 50and 100 Ω·cm² at 45° C. In yet other examples, the electrolyte has anASR of between 0 and 20 Ω·cm². In some other examples, the electrolytehas an ASR of between 0 and 10 Ω·cm².

In some examples, the electrolyte or composite electrolyte, herein, hasa room temperature Li⁺ ion conductivity greater than 10⁻⁵ S/cm.

In some examples, the electrolyte or composite electrolyte, herein, hasa room temperature Li⁺ ion conductivity greater than 10⁻⁴ S/cm.

In some examples, the electrolyte or composite electrolyte, herein, hasa room temperature Li⁺ ion conductivity greater than 10⁻³ S/cm.

In some examples, the electrolyte or composite electrolyte, herein,includes an inorganic material and an organic material in a weight ratioof (inorganic material):(organic material) of 0 to 99.

In some examples, the electrolyte or composite electrolyte, herein,includes an inorganic material and an organic material in a weight ratioof (inorganic material):(organic material) of at least 1:1 to 99:1.

In some examples, the electrolyte or composite electrolyte, herein,includes an inorganic material and an organic material in a weight ratioof (inorganic material):(organic material) of at least 80:20 to 99:1.

In some examples, the electrolyte or composite electrolyte, herein,includes an inorganic material and an organic material in a weight ratioof (inorganic material):(organic material) of at least 85:15 to 99:1.

In some examples, disclosed is an electrochemical cell which includes apositive electrode, a negative electrode, and a composite electrolytelayer. The composite electrolyte layer is positioned between thepositive electrode and negative electrode and includes a polymer and aninorganic solid state electrolyte. In some examples, the compositeelectrolyte layer which is positioned between the positive electrode andnegative electrode includes a composite electrolyte disclosed herein. Insome examples, the volumetric ratio of inorganic solid state electrolyteto polymer is >1. In some other examples, the volumetric ratio ofinorganic solid state electrolyte to polymer is greater than 1, 2, 3, 4,5, 6, 7, 8, 9, or 10. In some examples herein, the positive electrodeand negative electrodes directly contact an inorganic solid stateelectrolyte.

In some examples, set forth herein are composites of electrolytes andepoxides. In some examples, set forth herein are composites ofelectrolytes and epoxy resins. In some examples, the composites ofelectrolytes and epoxides, epoxy resins, or combinations thereof alsoinclude curatives, hardeners, additives, tougheners, flexibilizers,plasticizers, and other epoxy components. In some examples, thecomposite electrolytes set forth herein include any of the epoxides,epoxy resins, or components, analogs, and derivatives thereof which areset forth in “Epoxy Structural Adhesives,” in Structural Adhesives:Chemistry and Technology (1986), S. R. Hartshorn (ed.); or set forth in“Epoxy Resins,” by H. Q. Pham and M. J. Marks, in Ullmann's Encyclopediaof Industrial Chemistry (2010); or set forth in “Epoxy Resins,” by S. H.Goodman, in the Handbook of Thermoset Plastics, 2^(nd) Edition (1998)

As a general observation, mechanical characteristics of these compositeelectrolytes may improve as more polymers are added into thecompositions. However, excessive amounts of polymers may deteriorateelectrolyte characteristics. For example, the polymer may not conductlithium ions, in which case increasing the amount of polymer will reducethe conductance of the separator film leading to higher resistance andlower power. In another example, increasing the polymer content is aprocessing challenge because the specific polymer of choice may confer aviscosity that is either too high or too low to make the desired film.In some examples, the solid state electrolyte is mechanically mixed witha polymer and then extruded from the mixer to form composite thin films.If the viscosity is too high or too low, the extrusion process can bedetrimentally affected. In some examples, the solid state electrolyteand the polymer may phase separate, or the polymer may delaminate fromthe electrolyte, if the extrusion process is detrimentally affected by aviscosity that is either too high or too low. At the same time, theminimum amount of polymers needed to see any effects on mechanicalcharacteristics may depend on the solid electrolyte particle size,particle shape, and other like factors.

In the methods set forth herein, other processes may be substituted forextrusion processes. For example, casting methods may include extrusion,injection molding, melt processing, casting and calendering, drying andcalendering, wet calendering, wet milling and calendering, dry blending,and other known techniques in the relevant field for producing thinfilms

In some examples, disclosed is an electrochemical cell wherein theinorganic solid state electrolyte is spherical and has an aspect ratioof about 1. In certain examples, the inorganic solid state electrolyteis sintered or necked. As used herein, sintered means that the inorganiccomponents are denser, more compact, or in greater contact with otherinorganic components, than would be the case if the components were notsintered. Sintering of the components can be accomplished by heattreatment, pressure treatment, or both heat and pressure treatment. Asused herein, necked means that the inorganic components (e.g.,particles) are in contact with other inorganic components by way of, forexample, fused sides or edges, bonded sides or edges, or other particleto particle contact. Necked particles can form a network through thecomposite electrolyte through which Li⁺ ions can conduct.

In some examples, disclosed is an electrochemical cell wherein theinorganic solid state electrolyte is a lithium-stuffed garnetelectrolyte or a sulfide electrolyte. In some other examples, disclosedis an electrochemical cell, wherein the solid state electrolyte is alithium-stuffed garnet electrolyte characterized by the formulaLi_(y)La₃Zr₂O₁₂.XAl₂O₃, wherein 4≤y≤10 and 0<X≤1. In some examples, thesolid state electrolyte is a sulfide electrolyte characterized by theformula Li_(a)Si_(b)Sn_(c)P_(d)S_(e)O_(f), wherein 2≤a≤8, b+c=1,0.5≤d≤2.5, 4≤e≤12, and 0<f≤10; or Li_(g)As_(h)Sn_(j)S_(k)O_(l), wherein2≤g≤6, 0≤h≤1, 0≤j≤1, 2≤k≤6, and 0≤l≤10. In some examples, the solidstate electrolyte is an LPS:LiI electrolyte, wherein LPS is a mixture ofLi₂S:P₂S₅ having a molar ratio from about 10:1 to about 6:4, wherein andthe molar ratio of LPS:LiI is from 95:5 to 70:30.

In some examples, disclosed is an electrochemical cell wherein the solidstate electrolyte is a powder. In some other examples, the solid stateelectrolyte is a monolith back-filled with polymer. In certain examples,the powder is characterized by a particle size distribution (PSD)between about 0.5 μm to about 50 μm. In some examples, the powder ischaracterized by a particle size distribution (PSD) between about 10 μmto about 20 μm.

In some examples, disclosed is an electrochemical cell wherein thepolymer is selected from nitriles, nitrile butadiene rubber,carboxymethyl cellulose (CMC), styrene butadiene rubber (SBR),polybutadiene rubber (PB), polyisoprene rubber (PI), polychloroprenerubber (CR), acrylonitrile-butadiene rubber (NBR), polyethyl acrylate(PEA), polyvinylidene fluoride (PVDF), aqueous-compatible polymers,silicone, PMX-200 (polydimethylsiloxane, PDMS), methyl methacrylate,ethyl methacrylate, polypropylene (PP), polyvinylbutyral (PVB), polyethyl methacrylate (PMMA), polyvinyl pyrrolidone (PVP), atacticpolypropylene (aPP), isotactive polypropylene (iPP), ethylene propylenerubber (EPR), ethylene pentene copolymer (EPC), polyisobutylene (PIB),styrene butadiene rubber (SBR), polyolefins,polyethylene-copoly-1-octene (PE-co-PO), PE-co-poly(methylenecyclopentane)(PE-co-PMCP), stereo block polypropylenes, polypropylenepolymethylpentene copolymer, polypropylene carbonate, silicone,polyethylene (e.g., low density linear polyethylene), polybutadiene, andcombinations thereof.

In some examples, the polymer includes a non-conducting polymer. In someexamples, the polymer is not ion-conducting. In some examples, thepolymer included with the composite electrolytes described herein has aLi⁺ ion conductivity less than 10⁻⁵ S/cm. In some examples, the polymerincluded with the composite electrolytes described herein has a Li⁺ ionconductivity less than 10⁻⁶ S/cm. In some examples, the polymer includedwith the composite electrolytes described herein has a Li⁺ ionconductivity less than 10⁻⁷ S/cm. In some examples, the polymer includedwith the composite electrolytes described herein has a Li⁺ ionconductivity less than 10⁻⁸ S/cm,

In some examples, the polymer includes a polymer selected from nitriles,nitrile butadiene rubber, carboxymethyl cellulose (CMC), styrenebutadiene rubber (SBR), poly(vinylidene) fluoride (PVDF); PAN, PVC,aqueous-compatible polymers, atactic polypropylene (aPP), silicone,polyisobutylene (PIB), ethylene propylene rubber (EPR), PMX-200 PDMS(polydimethylsiloxane/polysiloxane, i.e., PDMS or silicone),polyacrylonitrile (PAN), polymethylmethacrylate (PMMA), polyvinylchloride (PVC), poly(vinylidene) fluoride-hexafluoropropylenePVDF-HFP.

In some examples, the polymer is chemically bonded to the electrolyte.In some of these examples, the polymer is physically or chemicallybonded to the electrolyte. For example, in some embodiments, the polymerincludes functional groups (e.g., carboxylate, thiol, hydroxyl) whichcan react with function groups or with reactive species in or on theelectrolyte. For example, the sulfur atoms in a sulfide electrolyte canbond to a thiol group on a polymer to form a bridging S—S bond whichadheres the polymer to the sulfide electrolyte's surface. In yet otherof these examples, the polymer is physisorbed to the electrolyte'ssurface. For example, in some embodiments, the polymer adheres to theelectrolyte by way of van de Waals forces. In some examples, the polymeris chemisorbed to the electrolyte's surface.

In some examples, the composite film has ceramic particles which havebeen functionalized with specific organic compounds to increase theadhesion between the ceramic and the polymer component. Thefunctionalization may be accomplished by covalent bonding, coordination,and, or physical adsorption.

In some examples, the covalent bonding approaches to improving theadhesive strength between the polymer and the ceramic may beaccomplished by reacting specific chemical functional groups with theceramic surface. In particular, those functional groups may be selectedfrom alkyl halides, anhydrides, epoxides, disulfides, isocynates,silanes, silicates, esters, hydroxyls, amines, amides, or nitriles.

In some examples, the coordination boding approaches to improving theadhesive strength between the polymer and the ceramic could beaccomplished by the interaction of the ceramic with specific functionalgroups, which may include carboxylates, esters, ethers, hydroxyls,amines, pyridines, amides, nitriles, phosphates, thioethers, or thiols.

In some examples, the physical adsorption approaches to improving theadhesive strength between the polymer and the ceramic could beaccomplished by using polymers of certain types, including thoseselected from the following classes: thioethers, alkyl ionic compounds,and homopolymers and block copolymers containing polar functionalities.

In some examples, disclosed is an electrochemical cell wherein thevolumetric ratio of inorganic solid state electrolyte to polymer isbetween 99:1 and 51:49.

In some examples, disclosed is an electrochemical cell wherein thepositive electrode includes oxide intercalation materials selected fromthe group consisting of LiMPO₄ (M=Fe, Ni, Co, Mn), Li_(x)Ti_(y)O_(z),wherein x is from 0 to 8, y is from 1 to 12, z is from 1 to 24, LiMn₂O₄,LiMn_(2a)Ni_(a)O₄, wherein a is from 0 to 2, LiCoO₂, Li(NiCoMn)O₂,Li(NiCoAl)O₂, and Nickel Cobalt Aluminum Oxides [NCA]. In some otherexamples, the positive electrode includes fluoride conversion chemistrymaterials are selected from the group consisting of FeF₂, NiF₂,FeO_(x)F_(3-2x), FeF₃, MnF₃, CoF₃, CuF₂ materials and alloys orcombinations thereof.

In some examples, disclosed is an electrochemical cell wherein thecomposite electrolyte is about 1 to 100 μm thick. In some examples, thecomposite electrolyte is about 20 μm thick.

In some examples, disclosed is a thin film electrolyte including aninorganic solid state electrolyte and a polymer, wherein the electrolytehas at least one textured surface. This texturing can be the result ofthe templating methods set forth herein, including, but not limited to,polymer particle templating, mesh templating, mesh imprinting, andrelated techniques. In some examples, the composite includes a polymerbond to at least one textured surface. In certain examples, the film hasa thickness that is between about 10 nm to 100 μm. In these examples,the inorganic electrolyte is exposed at both sides of highest surfacearea.

In some examples, disclosed is a thin film electrolyte wherein theinorganic solid state electrolyte is spherical and has an aspect ratioof about 1. In some examples, the inorganic solid state electrolyte issintered or necked. In certain examples, the inorganic solid stateelectrolyte is a lithium-stuffed garnet electrolyte or a sulfideelectrolyte.

In some examples, disclosed is a thin film electrolyte wherein theinorganic solid state electrolyte is a lithium-stuffed garnetelectrolyte or a sulfide electrolyte. In some other examples, disclosedis a thin film electrolyte, wherein the solid state electrolyte is alithium-stuffed garnet electrolyte characterized by the formulaLi_(y)La₃Zr₂O₁₂.XAl₂O₃, wherein 4≤y≤10 and 0<X≤1. In some examples, thesolid state electrolyte is a sulfide electrolyte characterized by theformula Li_(a)Si_(b)Sn_(c)P_(d)S_(e)O_(f), wherein 2<a≤8, b+c=1,0.5≤d≤2.5, 4≤e≤12, and 0<f≤10; or Li_(g)As_(h)Sn_(j)S_(k)O_(l), wherein2≤g≤6, 0≤h≤1, 0≤j≤1, 2≤k≤6, and 0≤l≤10. In some examples, the solidstate electrolyte is an LPS:LiI (LPSI) electrolyte, wherein LPS is amixture of Li₂S:P₂S₅ having a molar ratio from about 10:1 to about 6:4,wherein and the molar ratio of LPS:LiI is from 95:5 to 50:50. Examplesolid state electrolyte are found in U.S. Patent Application PublicationNo. US 2015-0171465, for U.S. patent application Ser. No. 14/618,979,filed Feb. 10, 2015 as a Continuation of International PCT PatentApplication No. PCT/US2014/038283, filed May 15, 2014. The contents ofeach of these applications in herein incorporated by reference in theirentirety for all purposes.

In some examples, disclosed is a thin film electrolyte wherein the solidstate electrolyte is a powder. In some examples, the powder ischaracterized by a particle size distribution (PSD) between about 0.5 μmto about 50 μm. In certain other examples, the powder is characterizedby a particle size distribution (PSD) between about 10 μm to about 20μm.

In some examples, disclosed is a thin film electrolyte wherein the solidstate electrolyte has a milled particle size of d₉₀ equal to about 5 μm.In some examples, the milled particle size of d₉₀ equal to about 1, 2,3, 4, 5, 6, 7, 8, 9, or 10 μm.

In some examples, disclosed is a thin film electrolyte wherein thepolymer is selected from nitriles, nitrile butadiene rubber,carboxymethyl cellulose (CMC), styrene butadiene rubber (SBR),polybutadiene rubber (PB), polyisoprene rubber (PI), polychloroprenerubber (CR), acrylonitrile-butadiene rubber (NBR), polyethyl acrylate(PEA), polyvinylidene fluoride (PVDF), aqueous-compatible polymers,silicone, PMX-200 (polydimethylsiloxane, PDMS), methyl methacrylate,ethyl methacrylate, polypropylene (PP), polyvinylbutyral (PVB), polyethyl methacrylate (PMMA), polyvinyl pyrrolidone (PVP), atacticpolypropylene (aPP), isotactive polypropylene (iPP), ethylene propylenerubber (EPR), ethylene pentene copolymer (EPC), polyisobutylene (PIB),styrene butadiene rubber (SBR), polyolefins,polyethylene-copoly-1-octene (PE-co-PO), PE-co-poly(methylenecyclopentane)(PE-co-PMCP), stereo block polypropylenes, polypropylenepolymethylpentene copolymer, polypropylene carbonate, silicone,polyethylene oxide (PEO), PEO block copolymers, polyethylene (e.g., lowdensity linear polyethylene), polybutadiene, and combinations thereof.In some of these examples, the volumetric ratio of inorganic solid stateelectrolyte to polymer is between 99:1 and 51:49.

In some examples, the polymer is a polymer selected from nitriles,nitrile butadiene rubber, carboxymethyl cellulose (CMC), styrenebutadiene rubber (SBR), poly(vinylidene) fluoride (PVDF); PAN, PVC,aqueous-compatible polymers, atactic polypropylene (aPP), silicone,polyisobutylene (PIB), ethylene propylene rubber (EPR), PMX-200 PDMS(polydimethylsiloxane/polysiloxane, i.e., PDMS or silicone),polyacrylonitrile (PAN), polymethylmethacrylate (PMMA), polyvinylchloride (PVC), poly(vinylidene) fluoride-hexafluoropropylenePVDF-HFP. In some of these examples, the volumetric ratio of inorganicsolid state electrolyte to polymer is between 99:1 and 51:49.

In some examples, disclosed is a thin film electrolyte wherein the filmis about 1 to 100 μm thick. In some examples, disclosed is a thin filmelectrolyte wherein the film is about 10 μm thick. In some examples,disclosed is a thin film electrolyte wherein the film is about 20 μmthick. In some examples, disclosed is a thin film electrolyte whereinthe film is about 30 μm thick. In some examples, disclosed is a thinfilm electrolyte wherein the film is about 40 μm thick. In someexamples, disclosed is a thin film electrolyte wherein the film is about50 μm thick. In some examples, disclosed is a thin film electrolytewherein the film is about 60 μm thick. In some examples, disclosed is athin film electrolyte wherein the film is about 80 μm thick. In someexamples, disclosed is a thin film electrolyte wherein the film is about90 μm thick.

In some examples, disclosed is a thin film electrolyte wherein the filmis about 10 μm thick and wherein the electrolyte has a surface roughnessless than ten (10) μm, less than five (5) μm, less than one (1) μm, orless than half (0.5) μm. In some examples, disclosed is a thin filmelectrolyte wherein the film is about 20 μm thick and wherein theelectrolyte has a surface roughness less than ten (10) μm, less thanfive (5) μm, less than one (1) μm, or less than half (0.5) μm. In someexamples, disclosed is a thin film electrolyte wherein the film is about30 μm thick and wherein the electrolyte has a surface roughness lessthan ten (10) μm, less than five (5) μm, less than one (1) μm, or lessthan half (0.5) μm. In some examples, disclosed is a thin filmelectrolyte wherein the film is about 40 μm thick and wherein theelectrolyte has a surface roughness less than ten (10) μm, less thanfive (5) μm, less than one (1) μm, or less than half (0.5) μm. In someexamples, disclosed is a thin film electrolyte wherein the film is about50 μm thick and wherein the electrolyte has a surface roughness lessthan ten (10) μm, less than five (5) μm, less than one (1) μm, or lessthan half (0.5) μm. In some examples, disclosed is a thin filmelectrolyte wherein the film is about 60 μm thick and wherein theelectrolyte has a surface roughness less than ten (10) μm, less thanfive (5) μm, less than one (1) μm, or less than half (0.5) μm. In someexamples, disclosed is a thin film electrolyte wherein the film is about80 μm thick and wherein the electrolyte has a surface roughness lessthan ten (10) μm, less than five (5) μm, less than one (1) μm, or lessthan half (0.5) μm. In some examples, disclosed is a thin filmelectrolyte wherein the film is about 90 μm thick and wherein theelectrolyte has a surface roughness less than ten (10) μm, less thanfive (5) μm, less than one (1) μm, or less than half (0.5) μm. In someexamples, disclosed is a thin film electrolyte wherein the film is about10 μm thick, wherein the electrolyte has a surface roughness less thanten (10) μm, less than five (5) μm, less than one (1) μm, or less thanhalf (0.5) μm, and wherein the electrolyte has exposed solid stateelectrolytes at the surface characterized by the surface roughness.

In some examples, disclosed is a thin film electrolyte wherein the filmis about 20 μm thick wherein the electrolyte has a surface roughnessless than ten (10) μm, less than five (5) μm, less than one (1) μm, orless than half (0.5) μm, and wherein the electrolyte has exposed solidstate electrolytes at the surface characterized by the surfaceroughness. In some examples, disclosed is a thin film electrolytewherein the film is about 30 μm thick, wherein the electrolyte has asurface roughness less than ten (10) μm, less than five (5) μm, lessthan one (1) μm, or less than half (0.5) μm, and wherein the electrolytehas exposed solid state electrolytes at the surface characterized by thesurface roughness. In some examples, disclosed is a thin filmelectrolyte wherein the film is about 40 μm thick, wherein theelectrolyte has a surface roughness less than ten (10) μm, less thanfive (5) μm, less than one (1) μm, or less than half (0.5) μm, andwherein the electrolyte has exposed solid state electrolytes at thesurface characterized by the surface roughness. In some examples,disclosed is a thin film electrolyte wherein the film is about 50 μmthick, wherein the electrolyte has a surface roughness less than ten(10) μm, less than five (5) μm, less than one (1) μm, or less than half(0.5) μm, and wherein the electrolyte has exposed solid stateelectrolytes at the surface characterized by the surface roughness. Insome examples, disclosed is a thin film electrolyte wherein the film isabout 60 μm thick, wherein the electrolyte has a surface roughness lessthan ten (10) μm, less than five (5) μm, less than one (1) μm, or lessthan half (0.5) μm, and wherein the electrolyte has exposed solid stateelectrolytes at the surface characterized by the surface roughness. Insome examples, disclosed is a thin film electrolyte wherein the film isabout 80 μm thick, wherein the electrolyte has a surface roughness lessthan ten (10) μm, less than five (5) μm, less than one (1) μm, or lessthan half (0.5) μm, and wherein the electrolyte has exposed solid stateelectrolytes at the surface characterized by the surface roughness. Insome examples, disclosed is a thin film electrolyte wherein the film isabout 90 μm thick, wherein the electrolyte has a surface roughness lessthan ten (10) μm, less than five (5) μm, less than one (1) μm, or lessthan half (0.5) μm, and wherein the electrolyte has exposed solid stateelectrolytes at the surface characterized by the surface roughness.

In some examples, disclosed is a composite electrolyte having theformula LPS:LiI (LPSI) wherein the molar ratio is from 10:1 to 1:1 Insome examples, the molar ratio is 9:1, 8:1, 7:1, 6:1, 5:1, 4:1, 3:1,2:1, or 1:1. In some examples, the molar ratio is 4:1, 3:1, 2:1, or 1:1.In some examples, the electrolyte has an ASR of 4, 3, 2, or 1, 2 cm² at60° C. when placed in a symmetrical Li—Li cell. In some of theseexamples, the composite further includes acetonitrile solvent (ACN). Insome other examples, the composite further includes polypropylene. Insome examples, the 1:1 LPS:LiI demonstrates an impedance of about 4.3Ωcm² at the Li-metal interface wherein measured at 60° C.

In some examples, disclosed is a composite electrolyte having LSTPS andpolypropylene (PP) wherein the volumetric ratio of LSTPS to PP is 10:1,9:1, 8:1, 8:2, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, or 1:1. In some of theseexamples, the composite further includes ACN. In some of these examples,the composite is in contact with Li-metal. In some of these examples,the composite is in contact with a gel having ACN solvent and a 1Mconcentration of a Lithium salt, such as LiPF₆.

In some examples, disclosed is a composite electrolyte having LSTPS andpolypropylene (PP) wherein the volumetric ratio of LSTPS to PP is 10:1,9:1, 8:1, 8:2, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, or 1:1. In some of theseexamples, the composite further includes dioxolane. In some of theseexamples, the composite is in contact with Li-metal. In some of theseexamples, the composite is in contact with a gel having a dioxolanesolvent and a 1M concentration of a Lithium salt, such as LiTFSI orLiPF₆.

In some examples, disclosed is a composite electrolyte having LSTPS andpolypropylene (PP) wherein the weight ratio of LSTPS to PP is 10:1, 9:1,8:1, 8:2, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, or 1:1. In some of theseexamples, the composite further includes EC:PC. In some of theseexamples, the composite is in contact with Li-metal. In some of theseexamples, the composite is in contact with a gel having a EC:PC solventand a 1M concentration of a Lithium salt, such as LiTFSI or LiPF₆. Insome of these examples, the composite and the gel show a low impedanceof about 10 Ωcm².

In some examples, disclosed is a composite electrolyte having LSTPS andpolypropylene (PP) wherein the composite has a minimum of 60 w/w % ofLSTPS (corresponding to 40 w/w % PP). In some examples, disclosed is acomposite electrolyte having LSTPS and polypropylene (PP) wherein thecomposite has a minimum of 70-80 w/w % of LSTPS (corresponding to 20-30w/w % PP).

In some examples, disclosed is a composite electrolyte having LSTPS andpolypropylene (PP), wherein the PP is isotactic polypropylene. In someexamples, the isotactic polypropylene has an average molecular weight of250,000 g/mol or greater.

In some examples, disclosed is a composite electrolyte having LSTPS andpolypropylene (PP) wherein the volumetric ratio of LSTPS to PP is about80:20 or 75:25. In some of these examples, the composite is in contactwith a gel. In certain examples, the gel includes PVDF polymer,dioxolane solvent and 1M concentration of LiFTSI or LiPF₆. In some otherexamples, the gel includes PVDF polymer, acetonitrile (ACN) solvent and1M concentration of LiFTSI or LiPF₆. In some of these examples, the gelhas a EC:PC solvent and a 1M concentration of a Lithium salt, such asLiTFSI or LiPF₆. In some of these examples, the composite and the gelshow a low impedance of about 10 Ωcm².

In some examples, disclosed is a composite electrolyte having LPS:LiI(2:1 or 1:1 v/v) and polypropylene (PP) wherein the volumetric ratio ofLSTPS to PP is about 80:20 or 75:25. In some of these examples, thecomposite is in contact with a gel. In certain examples, the gelincludes PVDF polymer, dioxolane solvent and 1M concentration of LiFTSIor LiPF₆. In some other examples, the gel includes PVDF polymer,acetonitrile (ACN) solvent and 1M concentration of LiFTSI or LiPF₆. Insome of these examples, the gel has a EC:PC solvent and a 1Mconcentration of a Lithium salt, such as LiTFSI or LiPF₆. In some ofthese examples, the gel has a succinonitrile solvent and a 1Mconcentration of a Lithium salt, such as LiTFSI or LiPF₆. In some ofthese examples, the composite and the gel show a low impedance of about10 Ωcm².

In some examples, disclosed is a composite electrolyte with a gel incontact with a lithium metal negative electrode. In these examples, thecomposite electrolyte is between the lithium metal negative electrodeand the gel.

In some examples, the composite electrolyte includes a polymer and aceramic composite with the polymer phase having a finite lithiumconductivity. In some examples, the polymer is a single ion conductor(e.g., Li⁺). In other examples, the polymer is a multi-ion conductor(e.g., Li⁺ and electrons). The following non-limiting combinations ofpolymers and ceramics may be included in the composite electrolyte. Thecomposite electrolyte may be selected from polyethyleneoxide (PEO)coformulated with LiCF₃SO₃ and Li₃N, PEO with LiAlO₂ and Li₃N, PEO withLiClO₄, PEO LiBF4-TiO₂, PEO with LiBF₄—ZrO₂. In some of thesecomposites, in addition to the polymers, the composite includes anadditive selected from Li₃N; Al₂O₃, LiAlO₃; SiO₂, SiC, (PO₄)₃, TiO₂;ZrO₂, or zeolites in small amounts. In some examples, the additives canbe present at from 0 to 95% w/w. In some examples, the additives includeAl₂O₃, SiO₂, Li₂O, Al₂O₃, TiO₂, P₂O₅, Li_(1.3)Ti_(1.7)Al_(0.3)(PO₄)₃, or(LTAP). In some of these composite electrolytes, the polymer present ispolyvinylidenefluoride at about 10% w/w. In some of these as compositeelectrolytes, the composite includes an amount of a solvent and alithium salt (e.g., LiPF₆). In some of these composites, the solvent isethyl carbonate/dimethyl carbonate (EC/DMC) or any other solvent setforth herein.

In some of the composite electrolytes set forth herein, the polymerserves several functions. In one instance, the polymer has the benefitof ameliorating interface impedance growth in the solid electrolyte evenif the polymer phase conductivity is much lower than the ceramic. Inother instances, the polymer reinforces the solid electrolytemechanically. In some examples, this mechanical reinforcement includescoformulating the solid electrolyte with a compliant polymer such aspoly paraphenylene terephthalamide. These polymers can be one of avariety of forms, including a scaffold.

Composite Material Components

Examples of binders, used to facilitate the adhesion between the oxide(e.g., garnet) or sulfide based particles, include, but are not limitedto, polypropylene (PP), polyvinyl butyral (PVB), poly methylmethacrylate (PMMA), poly ethyl methacrylate (PEMA), polyvinylpyrrolidone (PVP), atactic polypropylene (aPP), isotactivepolypropylene, ethylene propylene rubber (EPR), ethylene pentenecopolymer (EPC), polyisobutylene (PIB), styrene butadiene rubber (SBR),polybutadiene rubber (PB), polyisoprene rubber (PI), polychloroprenerubber (CR), acrylonitrile-butadiene rubber (NBR), polyethyl acrylate(PEA), polyvinylidene fluoride (PVDF), polyolefins,polyethylene-copoly-1-octene (PE-co-PO); PE-co-poly(methylenecyclopentane) (PE-co-PMCP); stereo block polypropylenes, polypropylenepolymethylpentene copolymer, poly propylene carbonate, methylmethacrylate, ethyl methacrylate, and silicone. Other binders includebinder is selected polypropylene (PP), atactic polypropylene (aPP),isotactic polypropylene (iPP), ethylene propylene rubber (EPR), ethylenepentene copolymer (EPC), polyisobutylene (PIB), styrene butadiene (SBR),polyolefins, polyethylene-co-poly-1-octene (PE-co-PO),PE-co-poly(methylene cyclopentene) (PE-co-PMCP), stereoblockpolypropylenes, polypropylene polymethyl pentene, polyethylene oxide(PEO), PEO block copolymers, silicone, polyethylene (e.g., low densitylinear polyethylene), polybutadiene, and combinations thereof.

Example binders include polyvinyl butyral. Binders may includepolycarbonates. Other binders may include polymethylmethacrylates. Theseexamples of binders are not limiting as to the entire scope of binderscontemplated here but merely serve as examples. Binders useful in thepresent disclosure include, but are not limited to, polypropylene (PP),atactic polypropylene (aPP), isotactive polypropylene (iPP), ethylenepropylene rubber (EPR), ethylene pentene copolymer (EPC),polyisobutylene (PIB), styrene butadiene rubber (SBR), polyolefins,polyethylene-co-poly-1-octene (PE-co-PO), PE-co-poly(methylenecyclopentane) (PE-co-PMCP), poly methyl-methacrylate (and otheracrylics), acrylic, polyvinylacetacetal resin, polyvinylbutylal resin,PVB, polyvinyl acetal resin, stereoblock polypropylenes, polypropylenepolymethylpentene copolymer, polyethylene oxide (PEO), PEO blockcopolymers, silicone, and the like.

Examples solvents suitable for use with the composites set forth hereininclude carbonates, acetonitrile, succinonitrile, toluene, benzene,ethyl ether, decane, undecane, dodecane.

Examples polymers for a polymer-sulfide composite include, but are notlimited to, polypropylene, polyethylene oxide (PEO), polyethylene oxidepoly(allyl glycidyl ether) PEO-AGE, PEO-MEEGE, polyethylene oxide2-Methoxyethoxy)ethyl glycidyl poly(allyl glycidyl ether) PEO-MEEGE-AGE,polysiloxane, polyvinylidene fluoride (PVdF), polyvinylidene fluoridehexafluoropropylene (PVdF-HFP), and rubbers such as ethylene propylene(EPR), nitrile rubber (NPR), Styrene-Butadiene-Rubber (SBR),polybutadiene rubber (PB), polyisoprene rubber (PI), polychloroprenerubber (CR), acrylonitrile-butadiene rubber (NBR), polyethyl acrylate(PEA), polyvinylidene fluoride (PVDF), polyethylene (e.g., low densitylinear polyethylene), and polybutadiene.

Examples solid state inorganic electrolyte includes, but are not limitedto, lithium super ionic conductor (LISICON), which includes a family ofsolids with the chemical formula Li_(2+2X)Zn_(1-X)GeO₄; Li₂S—SiS₂—Li₃PO₄(glass electrolyte), Li₁₀GeP₂S₁₂, Li-β-alumina, Li₂S—P₂S₅ (glasselectrolyte), Li_(3.25)Ge_(0.25)P_(0.75)S₄, Li₇P₃S₁₁, lithium phosphorusoxynitride (LiPON), 1.2Li₂S-1.6Lil-B₂S₃, or polyethylene glycol (PEG)with polyethyleneoxide (EO) polypropyleneoxide (PO) (3:1 EO:PO) withLi_(1.3)Al_(0.3)Ti_(1.7)(PO₄)₃.

Method of Making

The composites set forth herein can be made by a variety of methods.

Green Films

In some examples, set forth herein are composite electrolyte filmswherein the composite includes an inorganic electrolyte and a polymer.Prior to a heat treatment of a film having an inorganic and organiccomponent (e.g., polymer), the film is referred to as a “green film.” Insome examples, the inorganic electrolyte is lithium-stuffed garnetpowder, lithium-stuffed garnet chemical precursors, a sulfideelectrolyte, or a combination thereof. In some examples, these films areextruded in layers or deposited or laminated onto other compositeelectrolytes in order to build up several layers of a compositeelectrolyte. In some examples, these films are extruded as slurries thatoptionally include additional components. In some examples, theseadditional components include at least one member selected from abinder, a solvent, a dispersant, or combinations thereof. In someexamples, the solid loading is at least 50% by volume. In some examples,the film thickness is less than 100 μm.

In some examples, the dispersant in the green film is fish oil, MenhadenBlown Fish Oil, phosphate esters, Rhodaline™, Rhodoline 4160,phospholan-131™, BYK 22124™, BYK-22146™, Hypermer KD1™, Hypermer KD6™and Hypermer KD7™.

In some examples, the composite electrolytes films are extruded onto asubstrate. In certain examples, the substrate is a polymer, a metalfoil, or a metal powder. In some of these examples, the substrate is ametal foil. In some other examples, the substrate is a metal powder. Insome of these examples, the metal is selected from Ni, Cu, Al, steel,alloys, or combinations thereof.

In some examples, the green films have a film thickness less than 75 μmand greater than 10 nm. In some examples, these films have a thicknessless than 50 μm and greater than 10 nm. In some examples, the filmsinclude solid particles which are less than 5 μm at the particlesmaximum physical dimension (e.g., diameter for a spherical particle). Insome examples, the films have a median solid particle grain size ofbetween 0.1 μm to 10 μm. In other examples, the films are not adhered toany substrate. These films not adhered to any substrate are referred toas self-supporting or free standing.

In some examples, the composite electrolytes green films have athickness from about 10 m to about 100 μm. In some other of the methodsdisclosed herein, these film has a thickness from about 20 μm to about100 μm. In certain of the methods disclosed herein, the film has athickness from about 30 μm to about 100 μm. In certain other of themethods disclosed herein, the film has a thickness from about 40 μm toabout 100 μm. In yet other methods disclosed herein, the film has athickness from about 50 μm to about 100 μm. In still other methodsdisclosed herein, the film has a thickness from about 60 μm to about 100μm. In yet some other methods disclosed herein, the film has a thicknessfrom about 70 μm to about 100 μm. In some of the methods disclosedherein, the film has a thickness from about 80 μm to about 100 μm. Insome other of the methods disclosed herein, the film has a thicknessfrom about 90 μm to about 100 μm. In some of the methods disclosedherein, the film has a thickness from about 10 μm to about 90 μm. Insome other of the methods disclosed herein, the film has a thicknessfrom about m to about 80 μm. In certain of the methods disclosed herein,the film has a thickness from about 30 μm to about 70 μm. In certainother of the methods disclosed herein, the film has a thickness fromabout 40 μm to about 60 μm. In yet other methods disclosed herein, thefilm has a thickness from about 50 μm to about 90 μm. In still othermethods disclosed herein, the film has a thickness from about 60 μm toabout 90 μm. In yet some other methods disclosed herein, the film has athickness from about 70 μm to about 90 μm. In some of the methodsdisclosed herein, the film has a thickness from about 80 μm to about 90μm. In some other of the methods disclosed herein, the film has athickness from about 30 μm to about 60 μm. In some examples, the filmshave a thickness of about 1-150 μm. In some of these examples the filmshas a thickness of about 1 μm. In some other examples the films has athickness of about 2 μm. In certain examples, the films has a thicknessof about 3 μm. In certain other examples the films has a thickness ofabout 4 μm. In some other examples the films has a thickness of about 5μm. In some examples the films has a thickness of about 6 μm. In some ofthese examples the films has a thickness of about 7 μm. In some examplesthe films has a thickness of about 8 μm. In some other examples thefilms has a thickness of about 9 μm. In certain examples the films has athickness of about 10 μm.

In some examples, the composite electrolytes films set forth hereininclude an inorganic electrolyte combined with at least one or morepolymers. In some of these examples, the polymers include, but are notlimited to, polyethylene oxide (PEO), polypropylene oxide (PPO), PEO-PPOblock co-polymers, styrene-butadiene, polystyrene (PS), acrylates,diacrylates, methyl methacrylates, silicones, acrylamides, t-butylacrylamide, styrenics, t-alpha methyl styrene, acrylonitriles, vinylacetates, polypropylene (PP), polyvinyl butyral (PVB), polyvinylpyrrolidone (PVP), atactic polypropylene (aPP), isotactive polypropyleneethylene propylene rubber (EPR), ethylene pentene copolymer (EPC),polyisobutylene (PIB), styrene butadiene rubber (SBR), polyolefins,polyethylene-co-poly-1-octene (PE-co-PO); PE-co-poly(methylenecyclopentane), (PE-co-PMCP), stereoblock polypropylenes, polypropylenepolymethylpentene, polyethylene (e.g., low density linear polyethylene),polybutadiene, copolymer and combinations thereof.

Solutions and Slurries

In some examples, the methods herein include the use of solutions andslurries which are used to cast or deposit the composite electrolytefilms described herein. In certain examples, the inorganic electrolyte,or the chemical precursors to the inorganic electrolytes, are milled. Insome examples, these precursors are formulated into a slurry. In someexamples, these milled precursors are formulated into a slurry. Aftermilling, in some examples, the inorganic electrolytes, or the precursorsthereto, are formulated into coating formulations, e.g., slurries withbinders and solvents. These slurries and formulations may includesolvents, binders, dispersants, and/or surfactants. In some examples,the binder is polyvinyl butyral (PVB), polyvinylpyrrolidone (PVP), EthylCellulose, Celluloses, poly vinyl acetate (PVA), or PVDF. In someexamples, the dispersants include surfactants, fish oil,fluorosurfactants, Triton, PVB, or PVP. In some examples, the solvent isselected from toluene, methanol, ethanol, ethyl acetate,toluene:ethanol, benzene, dimethyl formamide (DMF), or combinationsthereof. In certain embodiments disclosed herein, the binder ispolyvinyl butyral (PVB). In certain embodiments disclosed herein, thebinder is polypropylene carbonate. In certain embodiments disclosedherein, the binder is a polymethylmethacrylate. In some embodimentsdisclosed herein, removing a solvent includes evaporating the solvent.In some of these embodiments, removing a solvent includes heating thefilm which contains the solvent. In some embodiments, removing a solventincludes using a reduced atmosphere. In still other embodiments,removing a solvent includes using a vacuum to drive off the solvent. Inyet other embodiments, removing a solvent includes heating the film andusing a vacuum to drive off the solvent.

Sintering Methods

In some examples, the methods set forth herein include a sintering step.In some of these examples, sintering includes heating the electrolytefilm or powder in the range from about 5° C. to about 1200° C. for about1 to about 720 minutes and in atmosphere having an oxygen partialpressure between 1e-1 atm to 1e-15 atm.

In some examples, the methods set forth herein include a sintering step.In some of these examples, sintering includes heating the electrolytefilm, powder, or precursor to about 1100° C. for about one to fourhours.

Single-Particle Thickness Extruded Films

In some examples, the methods set forth herein include making acomposite electrolyte having a thickness equal to about the scale of aninorganic electrolyte particle comprising the composite electrolyte. Insome of these examples, the method is substantially as set forth inFIG. 1. In Method 100 in FIG. 1, the method includes, as step 101,isolating monodisperse inorganic particles. These particles can includesulfide based or oxide based electrolytes, as set forth herein above andbelow. These particles can be, for example, 0.1, 0.2, 0.3, 0.4, 0.5,0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 μm inapproximate diameter. In some examples, the particles are spherical,approximately spherical, ellipsoidal, a particle shape with an aspectratio greater than 1. In some examples, the isolating monodisperseparticles includes identifying monodisperse particles. In some examples,the isolating monodisperse particles includes filtering monodisperseparticles to separate a give sized particle from a group of particleshaving a variety of sizes. In some examples, the filtering isaccomplished with centrifugation. In certain examples, these particlesare already calcined. The method set forth herein further includes, instep 102, mixing the particles with a binder, polymer, gel, organicsolvent, or combination thereof. The method set forth herein furtherincludes, in step 103, pressing, compacting, densifying, or casting afilm that includes the inorganic binders and the binder, polymer, and,or, organic solvent, in which the film is about the thickness of theinorganic particles. If the inorganic particles are about 20 μm indiameter, then the film that is cast is prepared (extruded, hotextruded, pressed, compacted, densified, cast) about 20 μm in thickness,shown as 104. The method set forth herein further includes, in step 105,etching or polishing one or two of the largest surface area sides of thefilm 104. This etching or polishing step results in the exposure of, orprotrusion of, the inorganic particles at or beyond the boundary of thebinder, polymer, gel or organic solvent, as shown in 106. As shown in106, the exposed inorganic particles can contact a positive or negativeelectrode without any organic material (e.g., binder, polymer, gel ororganic solvent) intervening between the positive or negative electrodesand the electrolyte.

In some examples, the films prepared by the above described method canbe illustrated as substantially set forth in FIG. 6. As shown in FIG. 6,film 601 has been surface treated so that the inorganic electrolyteparticles 602 extend beyond (or are exposed at) the 601 film's surface.In addition, the thickness of the film 601 is on the scale of the lengthof inorganic electrolyte particles 602. In another example, film 603 isillustrated in which oxide electrolyte particles 604 are exposed at, orextend beyond, the 603 film's surface. The thickness of the film 603 ison the scale of the diameter of inorganic electrolyte particles 604. Inthe composite films described herein, the inorganic electrolyteparticles can be ellipsoidal shaped (element 602), spherical (element604), substantially spherical, or also irregularly shaped. FIG. 6 ispresented for illustrative and representative reasons, but FIG. 6 is notdrawn to exact scale.

Particle-Templated and Back-Filled Film

In some examples, the methods set forth herein include making acomposite electrolyte that includes a solid state inorganic electrolyteand a polymer. In these methods, voids are introduced into a sinteredsolid state inorganic electrolyte. Next, a polymer is used, aftersintering, to back-fill any void spaces in the inorganic solid stateelectrolyte. As shown in FIG. 2, in some examples, the methods hereininclude a method for making a particle-templated and back-filled film.In some examples, the method includes step 201 for casting a green tape.This tape includes inorganic electrolyte materials or inorganicelectrolyte material precursors. In some of these examples, theinorganic electrolyte precursors include lithium stuffed garnetprecursors. In some other examples, the green tape also includesbinders, polymers, solvents, or combinations thereof. In addition to theabove, the green tape also includes spherical particles that can combustduring a subsequent sintering cycle, see step 202. In some examples,step 202 is a calcination step. In some of these examples, the sphericalparticles are approximately 6 μm in diameter. In some of these examples,the spherical particles are approximately 12 μm in diameter. In someexamples, the particles are made of polyethylene or, more specifically,from low density linear polyethylene. In another example, polybutadienestructures may be used. In yet other examples, the particles are made ofpolypropylene. In certain examples, the spherical particles areapproximately, 0.25, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 μm indiameter. In some examples, the methods includes a green tape whereinthe volumetric ratio of inorganic electrolyte, or inorganic electrolyteprecursor, to spherical particles (e.g., polyethylene or polypropylene)is about 1:10, 1:8, 1:6, 1:4, 1:2, 1:1, or 2:1. In certain examples, themethods include using a 1:2 volumetric ratio. In others, the volumetricratio is 1:1. In some of these examples, a lithium-stuffed garnetelectrolyte is mixed with polyethylene, wherein the polyethylene isapproximately 6 μm in diameter, in a 1:2 volumetric ratio(polyethylene:garnet). In some of these examples, a lithium-stuffedgarnet electrolyte is mixed with polypropylene, wherein thepolypropylene is approximately 12 μm in diameter, in a 1:1 volumetricratio (polypropylene:garnet). In some examples, the methods furtherinclude step 203 in which the green tape is sintered. In the sinteringprocess, the spherical particles combust (or otherwise volatilize fromthe film) and leave the green tape as gaseous combustion products. Thissintering step 203 densifies and crystallizes the inorganic electrolytewhile leaving vacant pores and voids where the spherical particles werepresent prior to the sintering process. In step 204, these pores andvoids are back-filled a polymer. This back-filled polymer can beincorporated as monomers in a solvent which are polymerized by methodsknown in the art, such as but not limited to photopolymerization,radical polymerization, or pH mediated polymerization. Once back-filledwith a polymer, the composite film having sintered inorganic electrolyteparticles and polymer is optionally polished in step 205. The polishingexposes inorganic electrolyte particles to the largest surface areasurface to the composite film. The polishing also results in a filmsurface which is flat and has uniform surface roughness. In someexamples, the polishing maximizes the amount of inorganic electrolytethat is exposed at the film surface in order to maximize the contactbetween the inorganic electrolyte component and the positive or negativeelectrodes which are interfacing with the polished film.

Particle-Templated and Back-Filled Film

In some examples, the methods set forth herein include making acomposite electrolyte that includes a solid state inorganic electrolyteand a polymer. In some these methods, the polymers which are suitablefor use (e.g., back-filling garnet voids) include those formed from freeradical polymerization of liquid monomers. Some of these polymersincludes acrylates, methacrylates, vinyl esters, styrenics,acrylonitriles, acrylamides. Monomers from the aforementioned polymercategories have, in some instances, multiple polymerizable functionalgroups on the same molecule (e.g. diacrylate and triacrylate monomers).In some embodiments, monomers having different functional groups may beused. In some embodiments, blends of monomers may be used in thepolymerization. In some embodiments, the monomers include those whichform cross-linked polymers (e.g., inside the garnet voids). In somethese methods, the polymers which are suitable for use (e.g.,back-filling garnet voids) include oligomers and low molecular weightpolymers, optionally, containing polymerizable functional groups. Insome these methods, the polymers which are suitable for use (e.g.,back-filling garnet voids) include oligomers and low molecular weightpolymers, optionally, containing polymerizable functional groups mayalso be used to generate crosslinked polymers in the garnet voids. Insome examples, the polymer is cross-linked polybutyl diene (PBD).

In some examples, the methods set forth herein include making acomposite electrolyte that includes a solid state inorganic electrolyteand a polymer. In some these methods, polymer back-filling includespreparing a solution containing monomer, free radical initiator, andsolvent. In some examples, this solution is applied to the garnetsurface (e.g, spin casting or drop casting. In some examples, thesolvent in the solution is then evaporated by, for example, spincoating, or by heating. In some of these examples, the monomer ispolymerized using heat (in the case of a thermal initiator) or UVexposure (in the case of a UV initiator).

As shown in FIG. 8, the green film having spherical particles therein isobserved to have a surface pattern that is representative of thespherical particles inside the green film. The particles assemble, asshow in FIG. 8, in a random fashion and leave imprints in the film thatare approximately spherical with an approximate diameter that matchesthe diameter of the spherical particle inside the green film.

Mesh-Templated and Back-Filled Film

In some examples, the methods set forth herein include making acomposite electrolyte that is templated by a polymer mesh. In some ofthese examples, as shown in FIG. 3, the method includes step 301 ofcasting a green tape of unsintered inorganic electrolyte, either in aprecursor form or in an already calcined form. In some examples, themethod further includes step 302 of casting the green tape onto apolymer mesh. As shown in step 302, the green tape is cast onto the meshso that the mesh is substantially covered by the green tape. The meshdoes not extend through the entire thickness of the film. In someexamples, step 302 is referred herein as imprinting. Rather, in someexamples, the mesh penetrates one side of the film about 1-50% of thethickness of the film. In some examples, the mesh imprints one side ofthe film about 1-50% of the thickness of the film. In the next step,303, the green tape and the polymer mesh are subject to sinteringconditions which densify the inorganic electrolyte in the green film andalso burn out, or combust, the organic constituents, including thepolymer mesh and any other organic compounds or materials which are incontact with the sintering green tape. After being sintered, a negativevoid imprint pattern remains in the sintered film and is characteristicof the template (e.g., polymer mesh, particles, and the like). This openvoid space is then, in step 304, back-filled with a polymer. In someexample, the method further includes, in step 305, polishing the side ofthe film having polymer on the surface and the side which would bond toan electrochemical electrode if the film were used in a device. Thepolishing exposes inorganic electrolyte particles at the largest surfacearea film side. The polishing or etching may also remove excess polymer.The polishing also results in a film surface which is flat and hasuniform surface roughness. In some examples, the polishing maximizes theamount of inorganic electrolyte that is exposed at the film surface inorder to enhance the contact between the inorganic electrolyte componentand the positive or negative electrodes which are interfacing with thepolished film.

In some examples, the methods set forth herein include making acomposite electrolyte that is templated by a polymer mesh. In some ofthese examples, as shown in FIG. 5, the method includes step 501 ofproviding a polymer substrate, which can include a polymer mesh, or amesh with engineered spaces (e.g., about or less than 20 μm inthickness). As shown in FIG. 5, the method in some examples includesstep 502 of printing a green film (e.g., a green tape havinglithium-stuffed garnet electrolyte particles, or a green tape havingchemical precursors to lithium-stuffed garnet electrolyte particles, andoptionally binders, polymers, and solvents). In some examples, themethod includes in step 502 casting a green tape of unsintered inorganicelectrolyte, either in a precursor form or in an already calcined form.In some examples, the method further includes step 502 casting the greentape onto a polymer mesh. As shown in step 502, the green tape is castor printed onto the mesh so that the mesh is substantially covered bythe green tape. The mesh does not extend through the entire thickness ofthe film. Rather, in some examples, the mesh penetrates one side of thefilm about 1-50% of the thickness of the film. In some examples, step502 is referred herein as templating. In some examples, the meshimprints one side of the film about 1-50% of the thickness of the film.As shown in FIG. 5, in some examples, the method includes step 503 inwhich the green tape and the polymer mesh are subject to sinteringconditions which densify the inorganic electrolyte in the green film andalso burn out, or combust, the organic constituents, including thepolymer mesh and any other organic compounds or materials which are incontact with the sintering green tape. After being sintered, a negativevoid imprint pattern remains in the sintered film and is characteristicof the template (e.g., polymer mesh, particles, and the like, seeprofile in step 503). This open void space is then, in step 504,back-filled with a polymer. In some example, the method further includespolishing the side of the film having polymer on the surface and theside which would bond to an electrochemical electrode if the film wereused in a device. The polishing exposes inorganic electrolyte particlesat the largest surface area film side. The polishing or etching may alsoremove excess polymer. The polishing also results in a film surfacewhich is flat and has uniform surface roughness. In some examples, thepolishing maximizes the amount of inorganic electrolyte that is exposedat the film surface in order to enhance the contact between theinorganic electrolyte component and the positive or negative electrodeswhich are interfacing with the polished film.

Imprinted and Back-Filled Film

In some examples, the methods set forth herein include making acomposite electrolyte that is imprinted by a polymer mesh template. Insome of these examples, as shown in FIG. 4, the method includes step 401of casting a green tape of unsintered inorganic electrolyte, either in aprecursor form or in an already calcined form. In some examples, themethod further includes step 402 of casting the green tape onto apolymer mesh. As shown in step 402, the green tape is cast onto the meshso that the mesh is substantially covered by the green tape. Also asshown in step 402, the mesh can be pressed into a green film. In some ofthese examples, step 402 includes imprinting the green film with thepolymer mesh. In some examples, step 402 is referred herein asimprinting. The mesh does not extend through the entire thickness of thefilm. Rather, in some examples, the mesh penetrates one side of the filmabout 1-50% of the thickness of the film. In some examples, the meshimprints one side of the film about 1-50% of the thickness of the film.In the next step, 403, the polymer mesh is removed from the green filmand leaves behind a negative pattern characteristic of the polymer meshpattern used to imprint it. In some examples, step 403 include peelingthe polymer mesh away from the green film. In some other examples, step403 include lifting the polymer mesh off of the green film. Once thepolymer mesh imprint is removed, the remaining green tape is, in someexamples, sintered in step 403 and as shown in FIG. 4.

In some examples, a green tape slurry is made and cast or pressed onto apolymer mesh. The polymer mesh can be any mesh that is suitable forimprinting a design or surface texture pattern to at least one side ofthe green tape. The polymer mesh should not be limited to those specificmeshes set forth herein. In an example, the mesh is polyester and has a320 mesh size, an 80 μm grid spacing, an 40 μm opening size, 25% openarea, and 40 μm wide diameter. In some examples, step 402 can includepartially encapsulating the polymer mesh on one side of the green filmby hot pressing the mesh into the unsintered green film at about100-200° C., 125-250° C., 125-150° C., 125-175° C., or 150-200° C. Insome examples, the polymer mesh is, in step 403, folded back and off ofthe green film.

In some examples, in step, 403, the green tape, having an imprintedpatter on at least one surface, is subject to sintering conditions whichdensify the inorganic electrolyte in the green film and also burn out,or combust, any organic constituents which may be present. See step 404.After being sintered, the imprinted pattern remains on the sinteredfilm's surface and is characteristic of polymer mesh's pattern. In someexamples, this imprinted pattern is referred to as a textured surface,or a surface having void spaces. In some examples, a portion of thistextured surface is, in step 405, back-filled with a polymer, selectedfrom the polymers and binders set forth herein. In some other examples,the voids created by the imprinted mesh are back-filled, in step 405,with a polymer, selected from the polymers and binders set forth herein.This open void space is then back-filled with a polymer. In someexample, the method further includes, in step 406, polishing the side ofthe film having polymer on the surface and the side which would bond toan electrochemical electrode if the film were used in a device. Thepolishing exposes inorganic electrolyte particles at the largest surfacearea film side. The polishing or etching may also remove excess polymer.The polishing also results in a film surface which is flat and hasuniform surface roughness. In some examples, the polishing maximizes theamount of inorganic electrolyte that is exposed at the film surface inorder to enhance the contact between the inorganic electrolyte componentand the positive or negative electrodes which are interfacing with thepolished film.

In some examples, certain steps, or all the steps together, can beautomated. For example, in FIG. 4, the steps 401, 402, and 403 could beconducted in a continuous fashion. For example, green film is cast ontoa imprinting design and then, in a continuous fashion, lifted off orremoved from the imprinted design at the same time that more film isbeing cast. In some examples, steps 401, 402, and 403 could be conductedsuch that the product of step 403 is immediately transferred to an oven,horizontal tube furnace, or oven having a conveyer belt design. In someexamples, the casting, imprinting, lift off, and sintering can all beconducted in a continuous fashion. In some examples, steps 401, 402, and403 may be conducted using a Gravure machine, a Rotogravure machine,impression roller, instrument, or the like.

Cracked and Back-Filled Film

In some examples, the methods set forth herein include making acomposite electrolyte wherein the method includes providing a film ormonolith which includes an inorganic solid state electrolyte. In someexamples, the methods further include cracking (or inducing a crack in)the film or monolith. For example, as shown in FIG. 7, film 702 is shownhaving cracks therein. After cracking the film, a polymer or a binder,selected from those polymers and binders described herein, isback-filled into the film and into the cracks in the film. As shown inFIG. 7, cracked film 702 is back-filled at cracks 701. Afterback-filling the film with a polymer or a binder, the film canoptionally be surface treated to remove any excess polymer or binder andto expose the inorganic electrolyte at the film's surface.

Polishing/Etching Surface of Composites

In some examples, the methods set forth herein include polishing oretching the surface of an solid state electrolyte composite in order tobetter expose the solid state electrolyte at the surfaces of a filmwhich have the largest surface area. For example, as shown in FIG. 28, acomposite 2801 is provided which has solid state inorganic electrolyteparticles (spheres) in a polymer matrix. By polishing or etching thesurface of the film having the largest surface area, top layer 2802 canbe removed which exposes middle layer 2803. Layer 2802 has lessinorganic electrolyte exposed at (or protruding from) the peripheralsurface as compared to layer 2803. Therefore, by etching away, orpolishing, layer 2802 to expose 2803, the amount of inorganic solidstate electrolyte accessible at the film's surface is maximized.

EXAMPLES Example 1—Making and Characterizing a Templated PorousLithium-Stuffed Garnet Solid State Electrolyte

In this examples, the steps shown in FIG. 2 were followed. Specifically,in this example, two green tape slurries, a first and second slurry,were made having, in the first slurry, approximately 6 μm diameterpolyethylene spherical particles, and in the second slurry,approximately 12 μm diameter polypropylene spherical particles. Aportion of the first slurry was mixed with garnet oxide electrolyteparticles in 1:2 polyethylene:garnet volume ratio, and a portion of thefirst slurry was mixed with garnet oxide electrolyte particles in 1:1polypropylene:garnet volume ratio. A portion of the second slurry wasmixed with garnet oxide electrolyte particles in 1:2 polyethylene:garnetvolume ratio, and a portion of the second slurry was mixed with garnetoxide electrolyte particles in 1:1 polypropylene:garnet volume ratio.Each of the four aforementioned slurries were cast as green films ofunsintered garnet particles. The green film were sintered at about 1100°C. for one to four hours to prepare porous garnet electrolyte (see step203 in FIG. 2 for an example of this step). FIG. 8 shows the surfaceroughness of a composite film formed from one of the second slurry whichhad the 12 μm diameter polypropylene spherical particles. FIG. 8 showsthat the surface roughness is directly related to the structure of thepolypropylene spherical particles which burned out as the porous garnetelectrolyte sintered around the template. FIG. 8 shows that the surfacefeatures on the sintered garnet are comparable with the scale of thepolypropylene spherical particles.

Example 2—Making and Characterizing an Polymer-Backfilled and ImprintedSintered Garnet Solid State Electrolyte

In this example, the steps shown in FIG. 4 were followed.

A first green tape slurry was made which included 70-90 um diametersized garnet particles and a polymer. The slurry was cast as a thin filmusing a doctor blade technique. After the film was cast, it wasimprinted with a polyester polymer mesh. The polyester polymer mesh hada 320 mesh size, an 80 μm grid spacing, a 40 μm opening size, 25% openarea, and 40 μm wide diameter. The polymer mesh was partially submerged(—25 μm penetration into the side of the film, corresponding to about25% of the total film thickness) into one side of the green film by hotpressing the mesh into the unsintered green film at about 125-175° C.The mesh was lifted off of the green film. FIG. 9 shows an optical imageof this imprinted green film. In this example, the sample imprinted witha nylon mesh is shown in FIG. 9. FIG. 9 shows that the top surface (901)of the film that was not imprinted with the polymer mesh was smooth.FIG. 9 shows that bottom surface (902) that was imprinted with thepolymer mesh retained the polymer mesh pattern after the pattern waslifted off the green tape. FIG. 10 shows the surface roughness of thetop and bottom surfaces of the imprinted film. FIG. 10 shows that theside of the film in direct contact with the polymer mesh (i.e., bottom)retains the spacing of the polymer mesh that was imprinted thereupon.

A first green tape slurry was made which included 70-90 um diametersized garnet particles and a polymer. The slurry was cast as a thin filmusing a doctor blade technique. After the film was cast, it wasimprinted with a polyester polymer mesh. The polymer mesh was made ofnylon and had a 198 mesh size, an 128 μm grid spacing, an 88 μm openingsize, 49% open area, and 40 μm wide diameter. The polymer mesh waspartially submerged (˜25 μm penetration into the side of the film,corresponding to about 25% of the total film thickness) into one side ofthe green film by hot pressing the mesh into the unsintered green filmat about 125-175° C. The polymer mesh was lifted off the green film andthe green film was sintered.

FIGS. 11-12 show Keyence VK-X100 surface roughness measurements of thesintered film. FIGS. 11-12 show that the pattern from the nylon mesh wastransferred to the sintered film. The peak-to-peak measurement shows adepth of channel at about 45 μm, which is comparable to the nylon meshdiameter. FIG. 13 shows an SEM image of the nylon imprint in thesintered garnet which is approximately 45 μm thick once sintered.

After sintering the green film, the sintered film had the morphology asshown in FIG. 13. In FIG. 13, one side of the film a surface texturethat is representative of the polymer mesh that was used to imprint thissurface texture into the sintered film. In a subsequent step, thesintered film was back-filled with a polymer. The resulting structure isshown in FIG. 14. In FIG. 14, layer 1402 includes a sinteredlithium-stuffed garnet oxide electrolyte. Layer 1401 is the polymer thatwas used to back-fill the surface pattern of the garnet electrolyte. InFIG. 14, the polymer used to back-fill the surface texture pattern ispoly(tri(propylene glycol) diacrylate).

Example 3—Making Lithium-Phosphorus-Sulfur-Iodide Solid StateElectrolytes and Composites Thereof by Extrusion Methods and Using theSame

In this example, a mixture of Li₂S:P₂S₅ (herein “LPS”) was prepared, inan 80:20 mole ratio. Then, the LPS was mixed with LiI in amounts of a1:1 molar ratio, a 2:1 molar ratio, and a 3:1 molar ratio wherein thismolar ratio can be represented by [LPS:LiI]. The resulting mixture wasthen annealed at 210° C., 300° C., or 400° C. Accordingly,(Li₂S:P₂S₅):(LiI), 2(Li₂S:P₂S₅):(LiI), and 3(Li₂S:P₂S₅):(LiI) solidstate electrolytes were made that were annealed at 210° C.;(Li₂S:P₂S₅):(LiI), 2(Li₂S:P₂S₅):(LiI), and 3(Li₂S:P₂S₅):(LiI) solidstate electrolytes were made that were annealed at 300° C.(Li₂S:P₂S₅):(LiI), 2(Li₂S:P₂S₅):(LiI), and 3(Li₂S:P₂S₅):(LiI) solidstate electrolytes were made that were annealed at 400° C. As shown inFIG. 15, certain compositions demonstrated a conductivity of 1×10⁻³ S/cmat 60° C. As shown in FIG. 15, lower annealing temperatures wereassociated with high conductivity values for the LPS:LiI compositions.Also as shown in FIG. 15, the 2(Li₂S:P₂S₅):(LiI) and 3(Li₂S:P₂S₅):(LiI)compositions were observed to have a higher conductivity than the(Li₂S:P₂S₅):(LiI) composition.

Conductivity measurements were performed by first cold pressing thepowder into a pellet of ½″ in diameter and approximately 1-1.5 mm inthickness. Next, Indium foil electrodes were applied to both sides ofthe pellet. Then, an AC signal was applied from a range of 1 MHz to 100mHz in a potentiostatic electrochemical impedance spectroscopymeasurement. Conductivity values were obtained by normalizing thecurrent response the geometry of the pellet.

Separate batches of 2(Li₂S:P₂S₅):(LiI) annealed at 210° C. wereprepared. After annealing, the electrolytes were formulated withpolypropylene and extruded as a composite of polypropylene and one ofthe aforementioned LPS compositions. The extrusion process includedmixing in a twin screw extruder at a temperature above the melting pointof polypropylene, followed by pressing of the extruded compositematerial in a heated press at a temperature above the melting point ofpolypropylene. The amount of LPS:LiI in the polypropylene was 80% w/w.As shown in FIG. 20, the composite was polished, 2002, and placedbetween two symmetric Li-metal electrodes, 2001 and 2003. The symmetriccell was subjected to 0.2 mA/cm² at 80° C. for 5 minute plating andstripping. This experiment conducted a 0.083 μm-thick layer of Li-metalfrom one side of the electrolyte to the other.

Example 4—Making and Using Lithium-Silicon-Tin-Phosphorus-Sulfur-IodideSolid State Electrolytes and Composites Thereof

In this example, Li₁₀Si_(0.5)Sn_(0.5)P₂S₁₂ (hereinafter “LSTPS”) was wetmilled to produce LSTPS particles having a d₅₀ particle diameter ofabout 50 nm to 500 nm. In this Example, LSTPS is referred to a compoundcharacterized by the formula Li₁₀Si_(0.5)Sn_(0.5)P₂S₁₂. The milledparticles were then filtered to produce a monodisperse particlecollection. The milled and filtered, monodisperse LSTPS particles werethen mixed in 75:25, 80:20, or 90:10 w/w ratios polypropylene polymer.The LSTPS polypropylene composite was hot press extruded to produce aLSTPS polypropylene composite film having a film thickness of about 65μm. The LSTPS polypropylene composite film was cast directly on a nickelfoil substrate.

The surfaces of the cast films were polished. FIG. 19 shows a plot ofASR for these LSTPS polypropylene composites. FIG. 21 shows the effectof polishing the LSTPS polypropylene composites as compared to notpolishing the LSTPS polypropylene composites. As shown in FIG. 21symmetric cells were constructed having either In electrodes (2101 and2103) or Li electrodes (2104 and 2106). An 80% w/w the LSTPSpolypropylene composite (2102 or 2105) was positioned in between thesetwo In or Li electrodes. The LSTPS polypropylene composite was polishedin one instance not polished in another instance. As shown in FIG. 21,the polished composites had lower ASR than their correspondingunpolished samples. Polishing conditions included hand polishing theLSTPS polypropylene composite surfaces to remove 5-20 microns ofcomposite using 2000 grit sand paper.

The polished LSTPS polypropylene composite films were placed betweenpositive and negative electrodes, both comprising Li-metal, in asymmetrical coin cell architecture. The coin cells were cycled at 50° C.and at either 0.5, 1, or 2 mA/cm². As detailed in Table 1, below, theLSTPS polypropylene composites in this configuration were observed tocycle at least 200 nm (0.04 mAh/cm²) of lithium between the electrodesand through the composite electrolyte. The observed results aretabulated below in Table 1.

TABLE 1 Li Plating/stripping Results. Current Plate/strip # of Amount ofLithium passed, I time Temperature cycles transferred per cycle (mA/cm²)(minutes) (° C.) completed 5 μm/cycle 0.5 120 50 50 5 μm/cycle 1.0 60 5050 5 μm/cycle 2.0 30 50 50 10 μm/cycle 0.5 240 50 50 10 μm/cycle 1.0 12050 50 10 μm/cycle 2.0 60 50 50 20 μm/cycle 0.5 480 50 50 20 μm/cycle 1.0240 50 50 20 μm/cycle 2.0 120 50 50

FIG. 22 also shows a benefit of polishing the LSTPS polypropylenecomposites in this Example. Without being bound to theory, it may bethat the polishing removes some polymer material the surface of theLSTPS polypropylene composite film and thereby exposes more solid stateLSTPS electrolyte at the sides interfacing the positive or negativeelectrode.

FIG. 23 also shows the benefit of polishing the LSTPS polypropylenecomposite. In this example, a symmetric electrochemical cell having Lielectrodes and an LSTPS-polypropylene composite therebetween was cycledat 80° C. and 0.1 mA/cm². The composite cycled for several cycles withan overpotential of about 6-7 mV.

FIG. 24 shows an example SEM image of a LSTPS-polypropylene compositedescribed herein. In this image, 2402 represents the LSTPS particles. Inthis image, 2401 represents the polymer surrounding the LSTPS particles.FIG. 24 also shows that the LSTPS-polypropylene composite isapproximately 80% w/w (by weight) of the composite with the remaining20% w/w being the polymer.

FIG. 30 shows the Li area specific resistance (ASR) for twoLSTPS-polypropylene composite films described in this Example, one whichwas treated with an Argon plasma to remove the organic polymer at thesurface of the LSTPS-polypropylene composite, and one which was nottreated as such. As shown in FIG. 30, by removing the polymer at thesurface, and exposing more of the inorganic electrolyte, the ASR wassubstantially reduced (i.e., improved).

Example 5—Making and Using Coin Cell Having aLithium-Silicon-Tin-Phosphorus-Sulfur-Iodide Solid State ElectrolyteComposite and a PVDF-Dioxolane-LiTFSI Gel Electrolyte

In this example, a coin cell was constructed with the followingcomponents assembled in series: a coil cell cap, a wave spring, a 0.5 mmSpacer, 12 mm thick layer of a gel electrolyte, 12 mm thick layer of a80:20 weight ratio LSTPS polypropylene composite, 10 mm of Indium foil,two 0.5 mm Spacers, and a coin cell case. The gel included PVDF with thesolvent dioxolane and the salt, lithium bis(trifluoromethane)sulfonimide(LiTFSI), at 1M concentration. The area-specific resistance (ASR) wasmeasured over 8 days using an potentiostatic electrochemical impedanceinstrument and a protocol which included 25 mV amplitude at 1 MHz to 100mHz. The results of this measurement, as shown in FIG. 25, show amoderate rise in impedance over the first day or two. After the firstday, the rate of impedance rise is decreased and is significantly sloweras time progresses.

Example 6—Making and Using Coin Cell Having aLithium-Silicon-Tin-Phosphorus-Sulfur-Iodide Solid State ElectrolyteComposite and a PVDF-EC:DMC:LiPF6 Gel Electrolyte

In this example, a coin cell was constructed with the followingcomponents assembled in series: a coil cell cap, a wave spring, a 0.5 mmSpacer, 12 mm thick layer of a gel electrolyte, 12 mm thick layer of a80:20 weight ratio LSTPS polypropylene composite, 10 mm of Indium foil,two 0.5 mm Spacers, and a coin cell case. In this example, the gelincluded PVDF with the solvent being a mixture of ethylene carbonate(EC): dimethyl carbonate (DMC) and the salt, LiPF₆, at 1M concentration.Area-specific resistance (ASR) was measured over several days using anpotentiostatic electrochemical impedance instrument and a protocol whichincluded 25 mV amplitude at 1 MHz to 100 mHz. The results in FIG. 26show that a low initial impedance with only a slight rise in impedanceafter the first day.

Additional LSTPS polypropylene composite were prepared having 23, 34,72, and 83 volume percentages of LSTPS, with the remainder being amajority polypropylene with a minority amount of binder. As shown inFIG. 29, which plots conductivity as a function of LSTPS volume percent,conductivity was observed to increase in proportion to the volumepercent of LSTPS in the composite.

Example 7—Making and Using a Lithium-Boro-Hydride-Iodide PolyPropyleneComposite (71 Vol % 3LiBH4:LiI, 29 Vol % Polypropylene)

In this example, LiBH₄ was mixed and annealed with LiI in a 3:1 molarratio. This resulting mixture was then formulated with polypropylene ina 71:29 volumetric ratio and extruded to form a composite. Thisresulting composite was polished, in one instance, and not polished inanother instance. Both the polished and unpolished samples were testedelectrochemically. This composite was placed in a symmetricelectrochemical cell with In electrodes. Electrochemical impedancespectroscopy (EIS) was performed at 80° C., the results of which areshown in FIG. 27. FIG. 27 shows that the samples which were polishedwere observed to have a lower ASR than the samples which were notpolished.

Example 8—Mechanical Strength Analysis of Solid State ElectrolytePolymer Composites

A set of experiments was conducted to identify stress-stain curves fordifferent composite electrolytes (i.e., different combinations of solidelectrolytes and polymers). Unless otherwise specified, the compositesin this Example were prepared by hot extrusion of the solid stateelectrolyte and the polymer.

FIG. 31 illustrates stress-stain plots for different combinations ofLi_(7.4)P₁₆S_(7.2)I (hereinafter “LPSI”) electrolyte particles andlinear low density polyethylene (LLDPE). LPSI is a material thatincludes LPS doped with LiI. LPSI is made by milling and mixing Li₂S,P₂S₅, and LiI, and then heat treating the milled mixture.

Line 3100 in FIG. 31 represents pure LLDPE and is presented herein forreference. Line 3102 represents a combination of 40% by weight of LPSIelectrolyte and 60% by weight of LLDPE. Line 3104 represents acombination of 60% by weight of LPSI electrolyte and 40% by weight ofLLDPE. Finally, line 3106 represents a combination of 80% by weight ofLPSI electrolyte and 20% by weight of LLDPE. Clearly, addition of LPSIelectrolyte reduces the strain tolerance of the resulting combination(as evidenced by the lower strain values). While additional LPSIelectrolyte may not be desirable from mechanical characteristicstandpoint, it may be needed for electrochemical reasons. Yieldstrength, yield strain, ultimate strength, and ultimate strain of theseexamples are further described below.

FIG. 32 illustrates stress-stain plots for different combinations ofLPSI electrolyte particles and cross-linked polybutadiene (PBD). Line3202 represents a combination of 80% by weight of LPSI electrolyte and20% by weight of PBD. Line 3204 represents a combination of 82% byweight of LPSI electrolyte and 18% by weight of PBD. Finally, line 3206represents a combination of 85% by weight of LPSI electrolyte and 15% byweight of PBD. Again, addition of LPSI electrolyte reduces the straintolerance of the resulting combination (as evidenced by the lower strainvalues). The effect is quite substantial when comparing lines 3202,3204, and 3206, which represent very small variations in the overallcomposition. Specifically, the fracture of 80%-20% combinationrepresented by line 3202 occurred at about 15.5%, while the fracture of82%-18% combination represented by line 3202 occurred at 4%. In otherwords, a very minor change (2% by weight) in the relative amounts of PBDand LPSI electrolyte yielded very different mechanical performance.Yield strength, yield strain, ultimate strength, and ultimate strain ofthese examples are further described below.

FIG. 33 illustrates stress-stain plots for different combinations ofLPSI electrolyte particles and polypropylene (PP). Line 3302 representsa combination of 40% by weight of LPSI electrolyte and 20% by weight ofPP. Line 3304 represents a combination of 60% by weight of LPSIelectrolyte and 40% by weight of PP. Finally, line 3306 represents acombination of 80% by weight of LPSI electrolyte and 20% by weight ofPP. Similar to the PBD and LLDPE examples presented above, addition ofLPSI electrolyte reduces the strain tolerance of the resultingcombination (as evidenced by the lower strain values). Yield strength,yield strain, ultimate strength, and ultimate strain of these examplesare further described below.

FIG. 34 is a summary of yield strength values for different compositeelectrolytes plotting these values as a function of LPSI loading. Line3402 is a trend-line for all tested LLDPE samples, line 3404 is atrend-line for all tested PP samples, and line 3406 is a trend-line forall tested PBD samples. Depending on the adhesive characteristics of thepolymer-ceramic interface, in some cases the yield strength may improvewith decreasing polymer content. In other cases, the yield strength willdecrease with decreasing polymer content. This data indicates thatdifferent polymers behave differently when combined with the same solidelectrolyte. This difference is attributable to mechanicalcharacteristics of different polymers as well as to binding of thesepolymers to LPSI particles. LLDPE appear to perform the best among thethree tested polymers at low (at or less than 20% by weight)concentrations of polymers.

FIG. 35 is a summary of ultimate strength values plotting these valuesas a function of LPSI loading. Line 3502 is a trend-line for all LLDPEsamples, line 3504 is a trend-line for all PP samples, and line 3506 isa trend-line for all PBD samples. The ultimate strength values decreasefor all types of polymers with the increase in the LPSI loading.However, the slopes of lines 3502, 3504, and 3506 are differentindicating the effects of the LPSI loadings on different polymers aredifferent. For example, changes in the concentration of PP appears tohave a greater impact on the ultimate strength than changes in theconcentration of LLDPE.

FIG. 36 is a summary of yield strain values plotting these values as afunction of LPSI loading. Line 3602 is a trend-line for all LLDPEsamples, line 3604 is a trend-line for all PP samples, and line 3606 isa trend-line for all PBD samples. The yield strain values decrease forall types of polymers with the increase in the LPSI loading with the PBDsamples showing the strongest dependence. Line 3606 representing PBDsamples has the greatest slope. PBD has the highest elasticity among thethree tested polymers, which explains this behavior.

FIG. 37 is a summary of ultimate strain values plotting these values asa function of LPSI loading. Line 3702 is a trend-line for all LLDPEsamples, line 3704 is a trend-line for all PP samples, and line 3706 isa trend-line for all PBD samples. Similar to the yield strain values,the ultimate strain values decrease for all types of polymers with theincrease in the LPSI loading with the PBD samples showing the strongestdependence.

FIG. 38A illustrates an SEM images of a fractured interface of a sampleincluding 82% by weight is LPSI and 18% by weight of PBD. FIG. 38Billustrates an SEM images of a fracture interfaced of a sample including80% by weight is LPSI and 20% by weight of PBD. It should be noted thateven with a very small increase (2% by weight) in the concentration ofPBD, the interface has visually more polymer strains extending betweenLPSI particles. The image of the 82%-18% sample appears to show that theLPSI particles are coated with PBD. However, there are much fewer PBDstrands extending between LPSI particles than in the 80%-20% sample.

Example 9—Making Lithium-Phosphorus-Sulfur-Iodide Solid StateElectrolytes and Composites Thereof by Free Radical PolymerizationMethods and Using the Same

In this example, 7 g of LPSI was mixed with 2.3 g of vinyl laurate, 0.6g of poly(ethylene-co-vinyl acetate) (40 wt % vinyl acetate), and 0.1 gof benzoyl peroxide to form a slurry. The slurry was pressed into a thinfilm at 23 MPa and heated to 110° C. for 30 minutes to initiatepolymerization of the vinyl laurate. Polymerization was monitoredvisually. Polymerization was completed when the liquid slurry was fullyconverted into a solid.

Example 10—Making Lithium-Phosphorus-Sulfur-Iodide Solid StateElectrolytes and Polybutadiene Composites Thereof by Solvent MixingMethods and Using the Same

In this example, 6 g of LPSI was mixed with 1.06 g of polybutadiene(Mw˜200,000), and 7.8 g toluene solvent. Toluene was removed byevaporation, and the resulting polymer composite was pressed into thinfilms of composite at 23 MPa and 250° C.

Example 11—Making Lithium-Phosphorus-Sulfur-Iodide Solid StateElectrolytes and Polybutadiene Composites Thereof by Solvent Mixing andExtrusion Methods and Using the Same

In this example, 6 g of LPSI was mixed with 1.06 g of polybutadiene(Mw˜200,000), and 7.8 g toluene solvent to form a mixture. Toluene wasremoved from the mixture by evaporation. The resulting polymer compositewas mixed in a twin-screw compounder and extruded to form small pellets.The extruded pellets were pressed into thin films of composite at 23 MPaand 250° C.

Example 12—Making Lithium-Phosphorus-Sulfur-Iodide Solid StateElectrolytes and Polybutadiene Composites Thereof by SolventCrosslinking Methods and Using the Same

In this example, 6 g of LPSI was mixed with 0.53 g of polybutadiene(Mw˜200,000), 0.53 g of predominantly 1,2-addition polybutadiene(incorporating approximately 90% 1,2-vinyl units), 0.03 g dicumylperoxide, and 7.8 g toluene solvent. Toluene was removed by evaporation,and the resulting polymer composite was mixed in a twin-screw compounderand extruded to form small pellets. Finally, the extruded pellets werepressed into thin films at 23 MPa and heated to 250° C. for 10 minutesto initiate crosslinking (i.e., vulcanization) of polybutadiene.

Example 13—Making Lithium-Phosphorus-Sulfur-Iodide Solid StateElectrolytes and Epoxide Composites Thereof by In-Situ Epoxy ResinCuring Methods and Using the Same

In this example, 2 g of LPSI was mixed with 0.4 g of bisphenol Adiglycidyl ether, 0.049 g of diethylenetriamine, and 1.2 g toluenesolvent. Toluene was removed by evaporation and the resulting dry powderwas pressed into a pellet under 280 MPa and heated at 100° C. for 10minutes to cure the pellet.

Example 14—Making Silane-Functionalized Lithium-Phosphorus-Sulfur-IodideSolid State Electrolyte and Composites Thereof

In this example, an LPSI (Li_(7.4)P_(1.6)S_(7.2)I) electrolyte wasfunctionalized with a silating agent. In one sample, 5 g of LPSI wasprovided. In a second sample, 5 g of LPSI was mixed with 25 g of a 5 wt% solution of trichloro(1H,1H,2H,2H-perfluorooctyl)silane in toluene andheated at 100° C. for 16 hours, subsequently separated bycentrifugation, and then washed three times with toluene. The LPSI withthe attached silane was dried under vacuum and then pressed into apellet at 25° C. under 175 MPa of pressure for 10 seconds. X-rayphotoelectron spectroscopy was used to confirm attachment of the surfacefunctionalizing agent via the silane functional group. See FIG. 39 whichshows that LPSI without the silane-functionalization. FIG. 39 shows thatLPSI without surface treatment shows no appreciable fluorine signal andweak signal at ˜320 eV due to adventitious carbon. See FIG. 40 whichshows that LPSI with the silane-functionalization. FIG. 40 shows thatLPSI after surface treatment withtrichloro(1H,1H,2H,2H-perfluorooctyl)silane shows strong fluorine signalat 710 eV, and strengthening of carbon signal at ˜320 eV:

Example 15—Making a Surface-functionalizedLithium-Phosphorus-Sulfur-Iodide Solid State Electrolyte and CompositesThereof Using a Polymer Coupling Agent

Two methods for incorporating surface coupling agents into LPSI-polymercomposites were performed in this Example.

Small Molecule Coupling Agent Approach. One method for incorporatingsurface coupling agents into LPSI-polymer composites includes using amolecule which includes (a) a functional group capable of surfaceattachment to sulfide electrolyte with (b) another functional group ableto participate in reactions with the polymer binder. Specifically, 5 gof LPSI was mixed with 25 g of a 5 wt % solution of3-methacryloxypropyltrichlorosilane in toluene and heated at 100° C. for16 hours to produce LPSI with a covalently attached silane. The LPSI wasseparated by centrifugation, and then washed three times with toluene.The LPSI with the covalently attached silane was finally dried undervacuum.

Pre-Formed Polymer Coupling Agent Approach. A second method forincorporating surface coupling agents into LPSI-polymer compositesincludes using a functionalized polymer that incorporates a functionalgroup or groups capable of surface attachment to sulfide electrolyte.Specifically, 5 g of LPSI was mixed with 25 g of a 5 wt % solution oftriethoxysilyl-modified poly-1,2-butadiene (a polybutadiene polymercontaining reactive silane groups pendant to the main chain) in tolueneand heated at 100° C. for 16 hours. The functionalized LPSI was then beseparated by centrifugation, and then washed three times with toluene.The LPSI with the covalently attached silane-functionalized polymer wasthen finally dried under vacuum.

This Example demonstrates that surface coupling agents can be bonded oradsorbed to the LPSI particle surface. This Example demonstrates that itis possible to incorporate a polymer binder phase into the composite andhave it associate with the LPSI particle surface. Other methods forincorporating a polymer binder phase into the composite so it associateswith the LPSI particle surface include direct covalent couplingreactions, e.g., crosslinking; copolymerization reactions; free radicaladdition reactions, addition-transfer reactions, or terminationreactions; epoxy curing (i.e., epoxide ring-opening) reactions;condensation reactions, or by entanglement or interpenetrating networkformation involving polymer chains attached to the sulfide surface andthose in the binder phase.

Example 16—Making a Surface-functionalizedLithium-Phosphorus-Sulfur-Iodide Solid State Electrolyte and CompositesThereof by Free Radical Polymerization

This coupling between sulfide and polymer binder in a composite wasachieved using either of the two following synthetic methods.

Two Step Approach: In this approach, the first step includespre-treatment of the sulfide electrolyte with the coupling agent, usingthe approaches in Example 15. Next, a polymer binder or with a monomeris mixed with the reaction mixture and allowed to cure to form thepolymer binder. This results in the coupling agent first attaching tothe sulfide surface (step 1), and subsequently to the polymer binder(step 2). Specifically, 5 g of LPSI was be mixed with 25 g of a 5 wt %solution of 3-methacryloxypropyltrichlorosilane in toluene and heated at100° C. for 16 hours. LPSI was then separated by centrifugation, andthen washed three times with toluene. The LPSI with the covalentlyattached silane was then be dried under vacuum. The dried LPSI with thecovalently attached silane was then used in a free radicalpolymerization reaction to form a composite wherein the methacryloxygroups attached to the LPSI were co-polymerized into the polymer binder.Specifically, 7 g of the surface-functionalized LPSI was mixed with 2.3g of vinyl laurate, 0.6 g of poly(ethylene-co-vinyl acetate) (40 wt %vinyl acetate), and 0.1 g of benzoyl peroxide. The mixture was pressedinto thin films at 23 MPa and heated to 110° C. for 30 minutes toinitiate polymerization of vinyl laurate.

One Step Approach: As an alternative to the two step approach, notedabove, a one-step approach may also be used. This methods includedmixing of the sulfide electrolyte, coupling agent, and polymer binder(or monomer pre-cursor), whereby the coupling agent attaches to both thesulfide electrolyte and the polymer binder in the same step.Specifically, 7 g of LPSI was mixed with 0.12 g of3-methacryloxypropyltrichlorosilane, 2.3 g of vinyl laurate, 0.6 g ofpoly(ethylene-co-vinyl acetate) (40 wt % vinyl acetate), and 0.1 g ofbenzoyl peroxide. The mixture was pressed into thin films at 23 MPa andheated to 110° C. for 30 minutes to initiate polymerization of vinyllaurate and drive reaction between the silane groups and the LPSIsurface.

Example 17—Making a Surface-functionalizedLithium-Phosphorus-Sulfur-Iodide Solid State Electrolyte and CompositesThereof by Coupling the Polymer Binder by Crosslinking Reaction

Small Molecule Coupling Agent, Two Step Approach: 5 g LPSI was firstmixed with 25 g of a 5 wt % solution of octenyltrichlorosilane intoluene and heated at 100° C. for 16 hours. LPSI was separated bycentrifugation, and then washed three times with toluene. The LPSI withthe covalently attached silane was dried and employed in thepolybutadiene composite process described in Example 15 above, such thatthe vinyl-containing octenyl groups attached to the LPSI wereco-crosslinked into the rubber matrix. 6 g of silane-functionalized LPSIwas then mixed with 0.53 g of polybutadiene (Mw˜200,000), 0.53 g ofpredominantly 1,2-addition polybutadiene (incorporating approximately90% 1,2-vinyl units), 0.03 g dicumyl peroxide, and 7.8 g toluenesolvent. Toluene was removed by evaporation, and the resulting polymercomposite was mixed in a twin-screw compounder and extruded to formsmall pellets. Finally, the extruded pellets were pressed into thinfilms at 23 MPa and heated to 250° C. for 10 minutes to initiatecrosslinking (vulcanization) of polybutadiene.

Small Molecule Coupling Agent, One Step Approach: 6 g of LPSI was mixedwith 0.055 g of octenyltrichlorosilane, 0.53 g of polybutadiene(Mw˜200,000), 0.53 g of predominantly 1,2-addition polybutadiene(incorporating approximately 90% 1,2-vinyl units), 0.03 g dicumylperoxide, and 7.8 g toluene solvent. Toluene was removed by evaporation,and the resulting polymer composite was mixed in a twin-screw compounderand extruded to form small pellets. Finally, the extruded pellets werepressed into thin films at 23 MPa and heated to 250° C. for 10 minutesto initiate crosslinking (vulcanization) of polybutadiene and to drivereaction between the silane groups and the LPSI surface.

Pre-Formed Polymer Coupling Agent, One Step Approach. In anotherprocess, a pre-formed polymer containing LPSI attachment groups was usedfor surface coupling. In this example, 6 g of LPSI was mixed with 0.53 gof triethoxysilyl-modified poly-1,2-butadiene, along with 0.53 g ofpolybutadiene (Mw˜200,000), 0.03 g dicumyl peroxide, and 7.8 g toluenesolvent. Toluene was removed by evaporation, and the resulting polymercomposite was mixed in a twin-screw micro-compounder and extruded toform small pellets. Finally, the extruded pellets were pressed into thinfilms at 23 MPa and heated to 250° C. for 10 minutes to initiatecrosslinking (vulcanization) of polybutadiene and to drive reactionbetween the silane functional groups on polybutadiene and the LPSIsurface.

Example 18—Making a Polymer Composite wherein a Surface-FunctionalizedSulfide Electrolyte is Coupled to the Polymer Binder by In-Situ EpoxyResin Curing

Small Molecule Coupling Agent, Two Step Approach:

In this example, 5 g LPSI was first mixed with 25 g of a 5 wt % solutionof (3-glycidyloxypropyl)trimethoxysilane and heated at 100° C. intoluene for 16 hours. LPSI was separated by centrifugation, and thenwashed three times with toluene. The LPSI with the covalently attachedsilane was dried and employed in the epoxy composite process describedin Example 13 above, such that the glycidyl groups attached to the LPSIcould be co-crosslinked into the epoxy matrix. In this example, 2 g ofthe surface-functionalized LPSI was mixed with 0.4 g of bisphenol Adiglycidyl ether, 0.049 g of diethylenetriamine, and 1.2 g toluenesolvent. Toluene was removed by evaporation and the resulting powder waspressed into a pellet under 280 MPa and heated at 100° C. for 10 minutesto effect curing and drive the reaction between the silane groups andthe LPSI surface.

Small Molecule Coupling Agent, Two Step Approach:

In this example, 2 g of LPSI was mixed with 0.022 g of(3-glycidyloxypropyl)trimethoxysilane 0.38 g of bisphenol A diglycidylether, 0.047 g of diethylenetriamine, and 1.2 g toluene solvent. Toluenewas removed by evaporation and the resulting powder was pressed into apellet under 280 MPa and heated at 100° C. for 10 minutes to effectcuring and drive the reaction between the silane groups and the LPSIsurface.

The following composites were made and tested based on the above Examplemethods.

Bulk LPSI conductivity From loading at 80° C. Example Polymer binder (wt%) Surface coupling agent (S/cm) 4 polypropylene 80 none 6.2e−5 5polyethylene 80 none 6.9e−5 10 polybutadiene 85 none 3.0e−4 9 poly(vinyl60 none 4.7e−5 laurate), poly(ethylene-co- vinyl acetate) blend 13bisphenol A 82 none 8.0e−4 diglycidyl ether, diethylenetriamine epoxypolymer 17 polybutadiene 85 octenyltrichlorosilane 3.7e−4 18 bisphenol A82 (3- 7.0e−4 diglycidyl ether, glycidyloxypropyl)trimethoxysilanediethylenetriamine epoxy polymer

The polyethylene sample (from Example 5) in the above Table was testedelectrochemically, as shown in FIG. 41.

The polybutadiene sample (from Example 10) in the above Table was testedelectrochemically, as shown in FIG. 42.

The bisphenol A diglycidyl ether, diethylenetriamine epoxy polymersample (from Example 13) in the above Table was testedelectrochemically, as shown in FIG. 43.

Example 19—Measuring Fracture Strength

FIG. 44 shows a ring on ring fracture test apparatus for testing thefracture strength of an electrolyte of the present disclosure. In thistest, for example, a 60 μm-thick, thin film composite electrolyte isplaced in a test fixture of two concentric rings (one of smallerdiameter than the other). The thin film composite electrolyte wascircular and 10 mm in diameter. The rings are then brought closertogether at a constant velocity. The force is recorded as a function ofdisplacement, as the thin film composite electrolyte film bends andeventually breaks. The thin film composite electrolyte fractures at aforce determined by its strength, which corresponds to the moment wherethe force drops. The fracture forces were recorded and analyzedstatistically.

CONCLUSION

The embodiments and examples described above are intended to be merelyillustrative and non-limiting. Those skilled in the art will recognizeor will be able to ascertain, using no more than routineexperimentation, numerous equivalents of specific compounds, materials,devices, and procedures. All such equivalents are considered to bewithin the scope and are encompassed by the appended claims

The language used in the specification has been principally selected forreadability and instructional purposes, and it may not have beenselected to delineate or circumscribe the inventive subject matter. Itis therefore intended that the scope of the disclosure be limited not bythis detailed description, but rather by any claims that issue on anapplication based hereon. Accordingly, the disclosure of the embodimentsis intended to be illustrative, but not limiting, of the scope of thedisclosure, which is set forth in the following claim.

1-179. (canceled)
 180. An electrolyte comprising an inorganic materialembedded in an organic material; wherein: the inorganic materialcomprises particles of inorganic material which form a percolationnetwork for lithium ion conduction through the electrolyte; the organicmaterial has a lithium conductivity of less than 10⁻⁸ S/cm at 80° C.,wherein the inorganic material comprises necked-particles of inorganicmaterial, the inorganic material is a solid state electrolyte, andwherein the solid state electrolyte is vLi₂S+wP₂S₅+yLiX, wherein X isselected from CI, I, or Br; and coefficients v, w, and y are rationalnumbers from 0 to
 1. 181. The electrolyte of claim 180, wherein theelectrolyte has a fracture strength of greater than 5 MPa and less than250 MPa.
 182. The electrolyte of claim 180, wherein the organic materialis molded around the inorganic material.
 183. The electrolyte of claim180, wherein the organic material comprises a functional group selectedfrom a carboxylic acid, an ester, an amide, an amine, a silane, sulfonicacid, a phosphate, a phosphine oxide, a phosphoric acid, an alkoxide, anitrile, a thioether, thiol, and combinations thereof; or wherein theorganic material has polar functional groups.
 184. The electrolyte ofclaim 180, wherein the organic material is polymerized around theinorganic material; wherein the organic material is entangled with theinorganic material; or wherein the organic material is entangled with asurface species which is present on the inorganic material.
 185. Theelectrolyte of claim 180, wherein the organic material is a polymer;optionally wherein one or more component of the organic material is apolymer selected from the group consisting of polyolefins, naturalrubbers, synthetic rubbers, polybutadiene, polyisoprene, epoxidizednatural rubber, polyisobutylene, polypropylene, polypropylene oxide,polyacrylates, polymethacrylates, polyesters, polyvinyl esters,polyurethanes, styrenic polymers, epoxy resins, epoxy polymers,poly(bisphenol A-co-epichlorohydrin), vinyl polymers, polyvinyl halides,polyvinyl alcohol, polyethyleneimine, poly(maleic anhydride), siliconepolymers, siloxane polymers, polyacrylonitrile, polyacrylamide,polychloroprene, polyvinylidene fluoride, polyvinyl pyrrolidone,polyepichlorohydrin, and blends or copolymers thereof, or wherein thepolymer is preformed and selected from the group consisting ofpolypropylene, polyethylene, polybutadiene, polyisoprene, epoxidizednatural rubber, poly(butadiene-co-acrylonitrile), polyethyleneimine,polydimethylsiloxane, and poly(ethylene-co-vinyl acetate); and whereinthe molecular weight of the polymer is optionally greater than 50,000g/mol.
 186. The electrolyte of claim 180, wherein the organic materialcomprises one or more polymerizable or crosslinkable members selectedfrom the group consisting of vinyl esters, acrylates, methacrylates,styrenic monomers, vinyl-functionalized oligomers of polybutadiene,vinyl-functionalized oligomers of polysiloxanes, and mixtures thereof,wherein the organic material comprises one or more crosslinkable membersselected from the group consisting of diglycidyl ethers, epoxy resins,polyamines, and mixtures thereof, wherein the organic material comprisesone or more polymerizable monomers selected from the group consisting ofvinyl esters, acrylates, methacrylates, styrenic monomers; wherein theorganic material comprises one or more crosslinkable members selectedfrom the group consisting of diglycidyl ethers, triglycidyl ethers,epoxy resins, polyamines; or wherein the organic material comprises oneor more crosslinkable oligomers selected from the group consisting ofvinyl-functionalized oligomers of polybutadiene, polysiloxanes, andmixtures thereof.
 187. The electrolyte of claim 180, where the organicmaterial comprises an epoxy resin; or where the organic materialcomprises an epoxy polymer precursor selected from the group consistingof bisphenol A diglycidyl ether (DGEBA), poly(bisphenolA-co-epichlorohydrin) glycidyl end-capped polymers, diethylenetriamine(DETA) and derivatives thereof, tetraethylenepentamine and derivativesthereof, polyethyleneimine, carboxyl-terminatedpoly(butadiene-co-acrylonitrile), amine-terminatedpoly(butadiene-co-acrylonitrile), poly(propylene glycol) diglycidylether, poly(propylene glycol) bis(2-aminopropyl ether), and combinationsthereof, and optionally wherein the organic material comprises an epoxypolymer precursor selected from the group consisting of bisphenol Adiglycidyl ether (DGEBA), poly(bisphenol A-co-epichlorohydrin) glycidylend-capped polymers, diethylenetriamine (DETA) and derivatives thereof,tetraethylenepentamine and derivatives thereof, polyethyleneimine, andcombinations thereof.
 188. The electrolyte of claim 180, where theorganic material comprises an epoxy polymer of bisphenol A diglycidylether (DGEBA), diethylenetriamine (DETA), and amine-terminatedpoly(butadiene-co-acrylonitrile); where the organic material comprisesan epoxy polymer of bisphenol A diglycidyl ether (DGEBA),diethylenetriamine (DETA), and poly(propylene glycol) bis(2-aminopropylether); where the organic material comprises a polymer of bisphenol Adiglycidyl ether (DGEBA) and poly(propylene glycol) bis(2-aminopropylether); or where the organic material comprises a polymer of bisphenol Adiglycidyl ether and diethylenetriamine (DETA); wherein thepoly(propylene glycol) bis(2-aminopropyl ether) optionally has amolecular weight (g/mol) of about 100 to 50,000.
 189. The electrolyte ofclaim 180, wherein the inorganic material has a silane attached to itssurface, wherein the silane is selected from trichlorosilanes,trimethoxysilanes, and triethoxysilanes; wherein the trichlorosilane is3-methacryloxypropyltrichlorosilane; wherein the trimethoxysilane is3-acryloxypropyltrichlorosilane; or wherein the trimethoxysilane is7-octenyltrimethoxysilane.
 190. The electrolyte of claim 180, whereinthe electrolyte is directly in contact with a gel electrolyte.
 191. Theelectrolyte of claim 180, wherein the electrolyte has a totalarea-specific resistance (ASR) of between 0 and 100 Ω·cm² at 45° C. 192.The electrolyte of claim 180, wherein the electrolyte comprises aninorganic material and an organic material in a weight ratio of(inorganic material):(organic material) from 1:1 to 99:1.
 193. Theelectrolyte of claim 180, wherein the organic material is apolymerizable or cross-linkable monomer.
 194. An electrochemical devicecomprising an electrolyte of claim
 180. 195. The electrolyte of claim180, wherein the organic material is selected from a preformed polymer,a monomer of a polymer, an oligomer, and combinations thereof, whereinthe organic material comprises

wherein n is an integer from 0 to 100,000; or wherein the compositioncomprises bisphenol A diglycidyl ether,

or any oligomer, polymer, or repeated unit thereof; and wherein theelectrolyte is prepared by mixing a preformed polymer with the inorganicmaterial, wherein the preformed polymer is optionally cured orcrosslinked after mixing with the inorganic material; or wherein theelectrolyte is prepared by mixing a polymerizable or crosslinkablemonomer or monomer blend with the inorganic material, and polymerizingor crosslinking the monomer(s) to form a polymeric organic materialin-situ.
 196. The electrolyte of claim 195, wherein the preformedpolymer is selected from the group consisting of polyolefins, naturalrubbers, synthetic rubbers, polybutadiene, polyisoprene, epoxidizednatural rubber, polyisobutylene, polypropylene oxide, polyacrylates,polymethacrylates, polyesters, polyvinyl esters, polyurethanes, styrenicpolymers, epoxy resins, epoxy polymers, poly(bisphenolA-co-epichlorohydrin), vinyl polymers, polyvinyl halides, polyvinylalcohol, polyethyleneimine, poly(maleic anhydride), silicone polymers,siloxane polymers, polyacrylonitrile, polyacrylamide, polychloroprene,polyvinylidene fluoride, polyvinyl pyrrolidone, polyepichlorohydrin, andblends or copolymers thereof, or wherein the polymerizing orcrosslinking monomer is selected from the group consisting of vinylesters, acrylates, methacrylates, styrenic monomers, diglycidyl ethers,epoxy resins, polyamines, and vinyl-functionalized oligomers ofpolybutadiene, polysiloxanes, and mixtures thereof.
 197. The electrolyteof claim 180, wherein the electrolyte has a fracture strength of 25 MPato 75 MPa.
 198. The electrolyte of claim 180, wherein the electrolytehas a fracture strength of 0.1 MPa to 200 MPa.
 199. A method for makingan electrolyte, comprising providing an inorganic material, wherein theinorganic material is a solid state electrolyte selected fromvLi₂S+wP₂S₅+yLiX, wherein X is selected from CI, I, or Br; andcoefficients v, w, and y are rational numbers from 0 to 1; providing anorganic material having a lithium conductivity of less than 10⁻⁸ S/cm at80° C.; mixing the inorganic and organic material to form a mixture;casting the mixture; and polymerizing the organic material; wherein themethod optionally comprises adding a polymer binder; wherein theelectrolyte comprises an inorganic material embedded in an organicmaterial; wherein the inorganic material comprises particles ofinorganic material which form a percolation network for lithium ionconduction through the electrolyte; and wherein the inorganic materialcomprises necked-particles of inorganic material.
 200. The method ofclaim 199, further comprising heating the mixture, wherein the mixtureis heated from about 200° C. to about 1000° C.